I'm trying to update my iPod and I want suggestions. I mostly like indie, rock, alternative, but I'll take anything. Thanks

Check out:
Super Fury Animals
Black Moth Super Rainbow
Explosions in the Sky
Cake
Queens of the Stone Age

If you are feeling extra adventurous:
Boards of Canada
Aphex Twin
Tycho
Pendulum
DJ Shadow
Monkeybacon
Infected Mushroom

How about the legendary song of Lit Up by Buck Cherry.
You can't have an iPod without it.
Always, you could play it safe with some Nickelback, Fall out Boy, Billy Talent, Zeromancer and stuff like that ?