So, what exactly does quirky mean? Um... I don't really know how to explain it, but it's still one of my favorite genres of TV or movies or whatever. It's probably also going to be mostly stuff I'd call dramedies, but still, there's something more to it than that, though I'll probably sometimes have trouble deciding whether to put some movies under "quirky," or comedy, or seriocomedy. But I'll do my best....
Anyway, I suppose my closest attempt to define "quirky" would be to say that it's simultaneously ordinary and out of the ordinary. The dictionary will probably tell you it's "unconventional," and I suppose it leans distinctly in that direction, but still I think most of the things I call quirky are in alot of ways pretty ordinary, which lends a rather convenient contrast to a subject's... unconventionality. You know wot I mean?
Familiar settings, a basically normal-seeming world (probably most often set in a small town), where things happen that may by contrast to that normalcy seem somewhat bizarre. Not bizarre enough to label a show "fantasy" or anything, though perhaps one might invoke the term "hyperreality." I don't know, some of the things I call "quirky" may include events that are anywhere from improbable to impossible, to the point I'm tempted to call it fantasy or some such genre, but not quite. And other things I call quirky may include nothing of the sort. Maybe it's just nothing more improbable than ordinary people being interesting and funny enough to make a movie or TV show about.
Which, when you think about it, is more improbable than it sounds, at least in real life. Yes, that's the ticket... if you're watching something about people who are, on the surface, no different than you or your friends, family, coworkers, whoever... and yet there's something you can't quite put your finger on that makes them more entertaining, makes them seem different somehow... that's probably quirky. Maybe. Or perhaps we could just call it "slice-of-more-interesting-life-than-yours." I dunno.
But basically, it's a convenient category that can include whatever I feel like calling quirky. I suppose the most useful explanation of what I mean by the term would be simply to watch (or at least read my reviews of) some of the different things I choose to include in the category.
See also quirky short films, quirky TV shows, and quirky webseries