I like everything! Well, not everything, but most things. Stuff with a beat you can dance to. Stuff that reminds you of movie scenes. Stuff you can listen to cleaning your house. Stuff that makes you feel good. Stuff that goes hand in hand with a sunny, cloudy or rainy day. I like it all. Except "nu-metal" or rap-rock or people who scream for no reason and Nickelback (especially Nickelback).
I'm really into finding new/lesser known bands now, but returning to the things that I liked in high school or early college is a new obsession. Pixies, Elliot Smith, Violent Femmes, Miracle Legion, The Smiths, old Ryan Adams, REM, The Frames and David Gray, even some vintage U2 (pre-world heroics)are all on my playlists.
I think everyone should have a soundtrack to their life and they should start by listening to wicked awesome music (which doesn't include Nickelback).