I run a label, and I thought perhaps we could pool some sites/people/etc we've had good experiences with?
A few good places who've been kind to us are;
Obviously some big ones are missing, but I assumed you'd think of them yourself, and a few here might be a bit predictable, but hopefully you'll find something you haven't tried before?
Not all of these guys are very big, but they're all very nice, and if you want some interesting responses to your music I recommend all of them.
There's obviously others, but I don't want to post a dissertation bibliography sized list...
Please post any you'd recommend.