Second on The Shins. If you don't have their stuff, get it now, they're such a fantastic band. Here's a big list of indie/alternative bands that I think are really good, in a rough order of how much I recommend them.

Well-known
Neutral Milk Hotel
Vampire Weekend
Guster
The Strokes
The Raconteurs (especially Consolers of the Lonely)
Yeah Yeah Yeahs (especially Show Your Bones)
Rogue Wave
The National

More Obscure
Electric President
Ra Ra Riot
Inkwell
Editors
The Autumn Defense
Cold War Kids
Voxtrot
The Grand Archives
The Muttering Retreats
Sun Kil Moon
My Morning Jacket
Hellogoodbye
Menomena
The Last Shadow Puppets
The Life and Times

Most of those are indie bands, and quite a few are very indie and only have one album out. And a lot of them won't be easy/possible to find on a public torrent tracker. Each and every one is at least worth looking up on Last.fm, though.