Badger M5, Hawkins, Surgeon and KMW all are good choices. I think the KMW is the most refined of the bunch, and while I don't have one, there's some clever features incorporated on the KMW that are lacking on the others.
The Badger M5 is pretty bare bones, works good if you want a lever type mag release. Surgeon has a larger paddle release, and a built in "barricade stop", which can be a handy feature. It's well machined as well. I don't have a Hawkins, but people seem to like those, and it's not too expensive.