Mainly I know him for his voice work. But I've also seen him in a few live action roles... I always remember his face and voice, but I just don't generally remember what I've seen him in. Which is what makes IMDb so useful! There's The Blues Brothers, Austin Powers, an episode of The 4400, an episode of Star Trek: Deep Space Nine, an episode of Ned's Declassified School Survival Guide, and well... IMDb lists guest spots on lots of shows where I'm sure I've seen him, but don't remember him so well, like I said...
I know him from Jurassic Park, Merlin, Bicentennial Man, Wimbledon, The Triangle, and voice work in Legend of the Guardians: The Owls of Ga'Hoole.
Nelson, Craig T.
I know him from Coach; and The Fire Next Time; and Parenthood; and Poltergeist; and voice work in The Incredibles.
I know him from Adventures in Babysitting; and a few eps of Designing Women; and Bull; and a small role in Fireflies in the Garden; and a minor role in Switching Channels; and and some voice work.
I know him from Batman; and The Shining; and Something's Gotta Give; and Mars Attacks!; and The Little Shop of Horrors; and Chinatown. Not sure if I've seen him in anything else, but of course I should, eventually.
I know him from Underworld; and The Hitchhiker's Guide to the Galaxy; and Pirates of the Caribbean: Dead Man's Chest (and At World's End); and Harry Potter and the Deathly Hallows, part 1; and Total Recall; and The Limehouse Golem; and Ordeal by Innocence; and voice work in Astro Boy; and Rango.
First and foremost, obviously, he is Star Trek's Spock. And um... well I'm sure I've seen him in some other stuff, unfortunately nothing quite so memorable... Oh, I do remember hearing him on the radio once in a remake of War of the Worlds, that was cool... And of course, I like his songs "The Ballad of Bilbo Baggins" and "Highly Illogical." Also, he voiced Mr. Moundshroud in The Hallowen Tree, General Konrad on Invasion America, and the Zarn in the Land of the Lost movie.
I guess I saw him in The Return of the King. And I saw a bit of Fringe, but I stopped watching after a few eps. (I later regretted that, and I'd really like to watch the whole series, someday.) I know him better from Sleepy Hollow; and season four of Elementary; and a few eps of Salvation.
Cliff on Veronica Mars, Gordy on Ned's Declassified School Survival Guide, Mr. Turner in Grow Up, Timmy Turner, Johnny Frost on a couple eps of iZombie, and various voice work.
I know him from Stand By Me; and My Secret Identity; and Sliders; and Scream 2; and Joe's Apartment; and a trifling role in The New Guy; and Mockingbird Lane; and the Veronica Mars movie; and a couple eps of Scream Queens.
O'Connor, Kevin J.
I know him from Deep Rising; and The Mummy; and The Others; and Van Helsing.
I know him from Heroes; and Hawaii Five-0; and minor roles in Get Smart; and Austin Powers in Goldmember; and Along Came Polly.
I know him from Bram Stoker's Dracula; and Leon: The Professional; and The Fifth Element; and Lost in Space; and Harry Potter and the Prisoner of Azkaban; and Batman Begins (and its sequels); and The Book of Eli; and Red Riding Hood; and he voiced Shen in Kung Fu Panda 2.
I know him from Psych; and Galavant; and a couple episodes of Supernatural; and a memorable ep of Lucifer; and an ep of Escape!; and an ep of Downward Dog.
I know him from Millennium; and Lost; and an ep of Masters of Science Fiction; and The Rocketeer; and Silver Bullet; and an ep of Star Trek: The Next Generation; and The Cutting Edge; and a small role in The X-Files: Fight the Future.
I know him from Gilmore Girls; and Supernatural; and A Ring of Endless Light; and Cry_Wolf.
I know him from Miss Guided; and 30 Rock; and Suburgatory; and Grown-ish; and I probably must have seen him on Saturday Night Live; and an episode of Miracle Workers; and surely some other stuff, including voice work (such as the Progressive Box in some Progressive insurance commercials).
I know him best from The Big Bang Theory. But there's also a minor role in Garden State; and The Muppets; and Wish I Was Here. And voice work in an episode of Eureka; and Elf: Buddy's Musical Christmas; and Michael Jackson's Halloween; and Marlon Bundo in an episode of Last Week Tonight. Also various commercials (mainly for Intel).
The first thing I remember him from is Profit. Later I saw a bit of Mysterious Ways, but I mainly know him for Heroes. There was also a recurring role in Agents of SHIELD. And I may have seen him in other stuff that I don't recall.
I know him from The Princess Bride; and Chicago Hope; and Alien Nation; and Dead Like Me; and a minor role in Dick Tracy; and Wish I Was Here. Possibly I've seen him in other stuff, I dunno.
Paxton, Bill (not to be confused with Bill Pullman)
I know him from Weird Science; and Aliens; and True Lies; and Twister; and Traveller; and Titanic; and Thunderbirds; and several episodes of Agents of SHIELD; and Edge of Tomorrow; and possibly some other stuff.
There were memorable recurring roles on Supernatural and Lost. And I guess a brief recurring role on Revolution, though I had forgotten about that. And a major role on The Tomorrow People. I may have seen him in some other stuff that I don't remember him from, but I wouldn't mind seeing more of his work.
I know him from Battlestar Galactica; and Dollhouse; and season 9 of Supernatural; and Trick 'r Treat; and The Portal; and I've surely seen him in things I've forgotten about.
I know him from Beauty and the Beast; and The Adventures of Captain Zoom in Outer Space; and the Hellboy movies; and Bunraku; and Season of the Witch; and Pacific Rim; and Alien Resurrection; and probably various live-action roles (most of which probably involve a bunch of makeup and prosthetics or whatever), but also a fair amount of voice work.
I know him from Lethal Weapon 2; and Goodfellas; and the Home Alone movies; and My Cousin Vinny; and I feel like there must be more than that, but maybe not.
I know him best from Star Trek: Voyager, but there's also Benson, the short film 9mm of Love, an episode of Deadbeat, and surely various things I'm forgetting.
I know him from Star Trek: Voyager; and China Beach; and The Wonder Years; and Morganville: The Series; and a couple episodes of The Orville; and surely things I've forgotten.
Pierce, David Hyde
I know him from The Powers That Be (though I don't remember that well); and Frasier; and When We Rise; and some voice work.
First and foremost I know him for The X-Files, of course. There was also Tarzan, several eps of Supernatural, and voice work on The Batman. Probably some guest roles in other things that I don't really remember.
I know him from the rebooted Star Trek movies; and Into the Woods; and voice work in Rise of the Guardians.
Liked him in The Red Green Show, Due South, and possibly some other stuff.
I know him from Thelma & Louise; and Cool World; and Interview with the Vampire; and 12 Monkeys; and Mr. & Mrs. Smith; and Babel; and voice work in Megamind.
I know him from Flatliners; and The Three Musketeers; and Bicentennial Man; and Don't Say a Word; and Pieces of April; and Casanova; and probably things I've forgotten. Also voice work in Legends of Oz: Dorothy's Return; and Wonder Woman.
I know him from The Sound of Music; and Star Trek VI: The Undiscovered Country; and Dracula 2000; and The Imaginarium of Doctor Parnassus; and Somewhere in Time; and 12 Monkeys; and A Beautiful Mind. He voiced Charles Muntz in Up; and 1 in 9; and I've probably seen or heard him in other stuff I don't remember. Plus he's done a ton of other things I've never seen, some of which I really should, someday.
I know him from a recurring role on The O.C.; and Guardians of the Galaxy; and Jurassic World; and some voice work, most notably in The Lego Movie.
I know him for narrating Tim Burton's short film Vincent; and a small role in Edward Scissorhands. I had a DVD one time with three of his movies, House on Haunted Hill, The Last Man On Earth, and The Bat. Didn't particularly enjoy any of them, really. Oh, and there was a cameo in one of those Beach movies. And he did a voiceover on Michael Jackson's "Thriller." And he voiced Ratigan in The Great Mouse Detective. I dunno if I've seen or heard him in anything else, but I'd like to.
Pullman, Bill (not to be confused with Bill Paxton)
I know him from Spaceballs; and A League of Their Own; and The Last Seduction; and Casper; and Independence Day; and Phoebe in Wonderland; and Torchwood (season 4); and 1600 Penn; and The Grudge; and Newsies; and he voiced Captain Korso in Titan A.E.
I know him from The New Guy; and a recurring role on Supernatural; and Comic Book Villains; and The Man in the High Castle.
I know him from Heroes; and Star Trek; and AHS: Murder House (and Asylum).
I know him from Xena: Warrior Princess; and Darkman; and the Evil Dead movies; and the Spier-Man movies; and My Name Is Bruce; and The Grudge; and the short film Semblance.
Mainly know him from The Wizard, I was big into that show while it was on. (If I was doing this list back then he'd have probably made the favorites page.) Of course he was also in Time Bandits. I'm afraid that... I think that's all I know him from...
I mainly know him from Cheers But there's also an ep of My So-Called Life; and M.A.N.T.I.S.; and Veritas: The Quest; and a bit of Warehouse 13; and A Christmas Carol; and A Midsummer Night's Dream; and a small role in The Scorpion King (though I didn't recognize him at all in that).
I know him from the Bill & Ted movies; and The Matrix movies; and Something's Gotta Give; and Speed; and Constantine; and A Scanner Darkly; and The Neon Demon.
Reilly, John C.
I know him from Chicago; and The Aviator; and A Prairie Home Companion; and Guardians of the Galaxy; and Cirque du Freak; and some voice work.
I know him from 28 Weeks Later; and The Unusuals; and The Avengers (and other movies in the MCU); and Hansel & Gretel: Witch Hunters; and American Hustle; and Arrival.
Rennie, Callum Keith
I know him from Due South; and Battlestar Galactica; and The Butterfly Effect; and Tin Man; and The X-Files: I Want to Believe; and undoubtedly other things that I've forgotten.
I know him as Pee-wee Herman from Pee-wee's Playhouse; and Pee-wee's Big Adventure; and Back to the Beach. I also know him for other roles, including a minor part in Batman Returns; and Mystery Men; and the original Buffy the Vampire Slayer movie; and an episode of Everybody Loves Raymond; and an episode of 30 Rock; and a couple eps of Gotham. And he voiced Lock in The Nightmare Before Christmas; and Max in Flight of the Navigator; and Fife in Beauty and the Beast: The Enchanted Christmas.
I know him from The Odyssey; and Two Guys, a Girl and a Pizza Place; and Waiting...; and Definitely, Maybe; and Adventureland; and X-Men Origins: Wolverine; and Green Lantern; and Fireflies in the Garden; and Van Wilder; and R.I.P.D.; and Life. Also voice work in The Croods.
I know him best for Sliders; but there's also the Lord of the Rings trilogy; and a couple of Indiana Jones movies; a couple eps of Star Trek: Voyager; a few eps of Krod Mandoon; and voice work in Aladdin & the King of Thieves and Gargoyles.
I first remember seeing him on Davis Rules, and I thought he was pretty cool on that. And then he was in several episodes of The Wonder Years, and an ep of The X-Files, and a few eps of Friends. And he was cool in Sky Captain and the World of Tomorrow. And maybe some other TV guest roles and stuff, I dunno. He was okay in Avatar, though it was a small role.
I know him from Nature of the Beast; and a few Roxy Hunter TV movies; and a few episodes of Supernatural; and a minor role in Percy Jackson: The Lightning Thief; and Urban Legend; and a minor role in The Last Halloween. He's also in Wrong Turn, but unrecognizable.
I know him from Dogma; and Galaxy Quest; and Robin Hood: Prince of Thieves; and Quigley Down Under; and Sweeney Todd; and the Harry Potter movies. He also did the voice of Marvin in The Hitchhiker's Guide to the Galaxy; and he narrated The Boy in the Bubble. Anyway, he's tremendously good at playing annoyed people. (But I think I sometimes confuse him with David Warner.)
I know him from Oscar; and Middle Ages; and The Mask. And I feel like I must have seen him in some other things, even minor guest roles or something, but I might be wrong, because I don't see anything else on IMDb that rings any bells. But I liked him in the few things I do remember.
I know him best from Three's Company, of course. But there's also Hooperman (which I barely remember), and It, and an episode of The Cosby Show, and Stay Tuned, and Hearts Afire, an episode of Buffy the Vampire Slayer, 8 Simple Rules (which I barely watched and didn't care for), and undoubtedly I saw him in some things I don't remember him from.
I know him from the Doctor Who TV movie; and Heroes; and The Dark Knight; and DOA: Dead or Alive; and The Expendables; and an ep of Brooklyn Nine-Nine; and some voice work. And, damn, I feel like I must've seen him in other stuff, I just don't remember...
I know him best from NewsRadio; and for some voice work. Also there was a minor role in Crocodile Dundee II; and Bicentennial Man; and True Blood; and a few episodes of Brooklyn Nine-Nine; and Get Out; and... looking at a list of his credits, there are a bunch of things I have seen him in that I don't specifically remember him from. But undoubtedly I enjoyed his work at the time, and if I saw any of those things again, I'd be like "Oh yeah, how the heck did I forget about that?"
I know him from Smallville; and a small role in Midnight in the Garden of Good and Evil; and Cursed; and the first season of Breaking In; and Urban Legend; and some voice work.
I know him from Ferris Bueller's Day Off; and Star Trek: Generations; and Spin City; and I Love You, Beth Cooper; and The Whispers; and The Exorcist; and I've seen him in several other things from which I don't remember him.
I know him from The Fire Next Time; and Clueless; and Romeo + Juliet; and The 40-Year-Old Virgin; and I Could Never Be Your Woman; and Forgetting Sarah Marshall; and The Perks of Being a Wallflower; and Ant-Man; and probably some things I've forgotten. Also some voice work, including Monsters vs. Aliens.
I know him from Escape from New York (and Escape from L.A.); and Big Trouble in Little China; and Overboard; and Dreamer; and Death Proof; and maybe some other stuff.