Let's see...
20. Isolee: Got this recently and am listening to it at the moment. So far, so good.
19. Pelican: Heard of, but haven't listened to. [Edit: No wait, they're metal, and I haven't heard of them. Stupid animal name bands. Nurr.]
18. Opeth: Too much of a pansy for metal

17. Yob: Never heard of.
16. Poker Flat. Never heard of.
15. The Juan MacLean: Never heard of.
14. Sigur Ros: Yes, please.
13. Serena Maneesh: Never heard of.
12. The Hold Steady: Never heard of.
11. Bell Orchestre: Never heard of.
10. The Decemberists: Definitely. Damn that crazy-ass (almost literally, if you consider his voice) Colin Meloy and "The Mariner's Revenge Song." The rest of the album was excellent too, though, so I would probably rank this higher than 10, but that's just me.
9. Spoon: Mm-mm good. Hey, am I the only who has an inexplicable urge to just strut about the house when listening to this album? Or turn my camera on?
8. Vitalic: Never heard of.
7. Clor: Never heard of.
6. Clap Your Hands Say Yeah: Good, but it would probably be lower on my list.
5. Broken Social Scene: Been trying to get my hands on it.
4. Deerhoof: Got this recently and am listening to it at the moment.
3. Animal Collective: Been trying to get my hands on it.
2. Wolf Parade: Personally, I would bump this up to number 1 (even though I like Sufjan). It was just that good.
1. Sufjan Stevens: See number 2.
That wasn't so bad. I got about half. [Checks to see if penis is intact.] Damnit, I only have half a wang now. Grr. I mean, nurr.