Damn I was gonna say hysteria lawl probably the best bass riff around but every bass player seems to learn that one though..
Dazed and confused by led zep is extremely easy
Seven nation Army is a no brainier.
The middle part of Paranoid Android by Radiohead sounds amazing and is pretty easy to play.
Red Hot chili's have tons of good bass riffs and the intro to Come As You Are by Nirvana is worth trying on bass.
Money by Pick Floyd sounds great and lastly I'd recommend Crazy Train by Black Sabbath
[Edited by Elite, 10/18/2009 10:29:12 AM]