Well I think you're already on to them from the What are you listening to thread, but definitely check out some Thursday.
While they do mix in some screamed vocals into their sound (a la Protest the Hero, only much less screaming), their main vocalist has a beautiful voice. Well, on their newest CD "A City by the Light Divided" anyway. (lol vocal coach)
I listen to some pretty niché/obscure stuff, so you might not have heard of any of these bands or may have trouble finding their music, but here goes anyway:
- Isis: Currently quickly rising up my favorite band's list. They treat each release as a complete artistic endeavor and their music is nothing short of innovative. Some very spacey carp going on here. However, I'll warn you ahead of time, they are primarily a metal band so there are some very harsh vocals at times (Growling and the like) but it's done in moderation as the vocals are kept to an absolute minimum as part of their philosophy on music. In particular, seek out their CD "Oceanic". It's what put them on the map and for damn good reason.
- Thrice (Not exactly obscure, but stfu): Thrice has been one of my favorite bands for as long as I can remember. They come from a screamo background but in their latest two releases, "Vheissu" and "The Alchemy Index" (Go after these discs first), have evolved into a very experimental rock style. I've seen them live twice and met them and got their autographs. They're totally grounded dudes and it shows in their music. Plus they've covered Eleanor Rigby and managed not to destroy it. You can't get more awesome than that.
- Pelican: Very atmospheric/experimental rock. They've been labeled an Isis wannabe band, but they've definitely come into their own. If you can find it, "The Fire in Our Throats Will Beckon the Thaw" is an amazing disc.