^^ Understatement! To quote a friend of mine: Tool > every other band.
That being said...
Clutch (Not really metal, more stoner rock, but just as good)
Death
Hatebreed
Lamb of God
Shadows Fall
Down
Mudvayne's L.D.50 is far superior to anything else they've put out IMO
The Bled
And now for something completely different...
The Dillinger Escape Plan
PsyOpus
Pig Destroyer
Tiwanaku (I believe they only have a 4 song demo floating around the net, but it's wonderfully different)
Finally, a band of which I've only recently been introduced, Crotchduster.