I own ( ) by Sigur Ros on cd and think it's great. The kind of music you can just sit and let it wash over you. Great for working along to because the lack of any real lyrics stops me getting too carried away.
I'm a big fan of Kaiser Chiefs (was at their homecoming gig in Leeds last week, truly amazing, still got a sore throat) The Young Knives, Goldfrapp, Pigeon Detectives and the Wombats. Almost all my music is bought on cd. I use iTunes to buy single songs. For example, if I'm watching t.v. and I hear a song I like I'll bash as many lyrics as I can catch into google to find out what song it was and then nip into iTunes to buy it.
Oops can't forget Seasick Steve.