MicShazam

I am pretty damn selective about what I actually let into the holy temple that is my album collection. I spend most of my time listening to stuff that I know I like. Currently, that means 128 different artists, just under half of which I consider my favorites.
On top of that there's the many artists I know of and maybe did own albums with at some point, but who I got a bit bored with. There are tonnes of bands like that, which I like in small doses but don't need to actively seek out.

In terms of genres, it slowly grows wider year by year and I wouldn't say there's all that much that I'm missing in my collection (unless we're getting into specific sub genres, of which there are thousands). I've got no screamo, no country (I like a bit of Neko Case, though: Exhibit A), no rap (although I have stuff that contains rap elements). Can't stand surfer rock, rockabilly or ska. Then there are some of those contry-specific crap genres that old people listen to (exhibit B). I avoid that stuff when possible. Mostly though, I'm open to new sounds and I do enjoy variety. Life would be very boring if one never looked to new horizons, but I can't say that I'm listening to thousands of artists. I strongly prefer to dedicate a good amount of time to the music that fascinates me the most.

EDIT: Forgot ambience. I have no interest in ambient, probably never will have.

Exhibit A: I like this song. Its... partially country at least.

Exhibit B. Danish band called Kandis. Horrible old-people-muzak.