Do any of you guys play Rock Band? If so, then what is your favorite instrument, (guitar, bass, drums, vocals) and what are your favorite songs to rock out to, what difficulty do you play on? Let us all know!

I play on Bass, I can play guitar and sing as well. My average difficulty is hard, but I can play some songs on expert.
Favorite songs to play are.....

The Moving Pictures album from Rush, all 7 songs
The Trees from Rush
White Wedding from Billy Idol
I.V. from X Japan
Still Alive from GLaDOS and Jonathan Coulton
Skullcrusher Mountain by Jonathan Coulton
Headphones On by Miranda Cosgrove
All the Boston songs.

Ugh, I'm gonna stop there, too many to list, lol.