A selection of suggestions for the mix tape from Blue and Brown and Dan, up form the comments.
Firstly, blue and brown's, note that there is a ban on all coldplay:
Apologies to Insect Life - British Sea Power.
The Test - The Chemical Brothers
Nature Boy - Nick Cave and the Bad Seeds
Bovine Spungiform Economics - Million Dead
Biological - Air
Gene By Gene - Blur
Tendon #7 - Chris TT [late addition due to non-emo nature, that and the fact that he lists Dawkins, Darwin, the Nat. Hist. and Sherlock's bro as influences on his MySpace thingymajigger, good man.]
(I'm going to ignore the rest of Dan's as they are either too emo, or I havn't heard of them... Or both)