We tend to like a lot of the same music, lately this includes,(In no particular order):
Death Cab for Cutie,
Wilco,
Muse,
Coldplay,
Dave Matthews Band,
Modest Mouse,
The Shins,
The White Strips (and Racontours)
She tends not to like much Jazz or Classical, since she likes songs with vocals mostly, but she does not mind when I put some on. My only complaint is that she dislikes music that is, what she calls "moldy oldies", which basically means anything older than 10-20 years old, which includes The Beatles, Stones, The Who, Pink Floyd, etc. (Which is weird, as she grew up with all of that music, as she and I are both close to 50.) All in all, at least she (mostly) supports my hobby, so I am happy about that, and she loves the fact that I am always finding new musical groups to expose her too.