Someone might already have mentioned them, but High On Fire and Monster Magnet are incredible. It's hard to go wrong with them. Reiterating what others have said, Kyuss, QOTSA, and Sleep are essential stoner banRAB. Electric Wizard is excellent stoner metal, of the slow and doomy variety. I don't think I've seen Sixty Watt Shaman mentioned, but they were good. They only had a couple of albums.
If the original poster likes stoner rock, he'd probably like doom. I recommend the excellent Reverend Bizarre.