I grew up a child of the 90s, not really the Grunge movement but the stuff that came out of it. So stuff like Foo Fighters, Tool and Perfect Circle, Soundgarden, Bush, Smashing Pumpkins, Alice in Chains, Silverchair, Sponge, Bad Religion, Deftones, they always find their way to my playlists. The more recent stuff I listen to tends to follow that path too: Rise Against, Anberlin, 32 Leaves, Red, Skillet, Breaking Benjamin, Disturbed, Three Days Grace, Chevelle. Pandora serves me up quite a bit at work, and I'll usually give an artist at least a listen.
But I also was raised with a lot of classic rock around, and I find myself sticking with some of the real creative forces there. Obvious stuff like Led Zeppelin and Pink Floyd, sure, but also King Crimson, Rush (2112 > Moving Pictures), Kansas, The Clash, Depeche Mode, they aren't going anywhere either.
To say nothing of my love of vidja gaem musik. A shout out to my boy
SupraDarky, who's been picking the best game music for nearly a decade now for playlists and whose lists I tend to have running in the background whenever I'm playing an MMO or otherwise doing something where the audio isn't too important. Highlights of my recent listens include the obligatory Chrono Cross mention, the realization that Umineko's soundtrack is way more awesome than you would expect from a Visual Novel, and the reminder that Neir was seriously underrated as a game and soundtrack.