This may sound cliche because Guitar Hero ruins everything good (OH GOD, MY BELOVED "YYZ"!), but all of "Reptilia" by the Strokes is pretty fuckin' fun to play, especially since it impresses the shit out of anybody you play it for. Bonus points when you get to the part that's all like this:
e--10-10-----10=5-5-----5=7-7-----7=9-9-----9=7-7-----7=9-9-----9=5-5-----5=10-10
a--------------------------------------------------------------------
b-------------------------------------------------------------------
d---9---9------9=4-4-----4=5-5-----5=7-7-----7=5-5-----5=7-7-----7=4-4-----4=9--9
a--------------------------------------------------------------------
e-------------------------------------------------------------------
Kinda rough, but you get the idea. The part that's immediately after that is even MORE impressive to people you play it for. Also, another band with some pretty excellent guitar work is Billy Talent. Specifically, check out Billy Talent II. "Pins and Needles", "The Navy Song", "Surrender", and "Try Honesty" have some pretty excellent, pretty complicated riffs, courtesy of Ian D'Sa. A lot of that band's stuff is really crappy, campy, and honestly seems as 'filler'-y as it gets, but when they've got gems, they've got gems.