Originally hailing from Germantown, MD... near my old stomping grounds but far from my current culture-starved locale... Clutch is one of the largely unsung greats of the rock 'n' roll universe.
Depending on the album, they careen around between blues, stoner rock, and beer metal, but always with a groovy heaviness and a really fat sound. If you listen to them for about thirty seconds or less it might be easy to dismiss them as a 'typical' (though not really so common these days) but tight bar band. But give them just a little time, and their genius becomes apparent.
Neil Fallon has an appealing whiskey-soaked delivery but his lyrics are what will really get your attention. Lots of wordplay, literary and mythological allusion, and cultural insight all fittting music that seems about as far from an appropriate vehicle for it as is possible to get. But it works. Very clever stuff. And the music works a similar angle. If one could use the word 'progressive' within the bar band sound then that might be a correct tag. Clutch really 'explores the space' (sorry BOC) of the stoner rock/metal sound and always keeps things interesting.
If you like bands like Brand New Sin, or to reference something more mainstream Black Stone Cherry, Clutch is like a mind-bent cousin, in the same way Corrosion of Conformity might be but without the harshness that band sometimes pushes.
Get on itunes and check out From Beale Street to Oblivion, their most accessible album, and if it appeals work your way up to their magnum opus Blast Tyrant. You really can't go wrong with any of it. Along with King's X these guys would probably be on the top of my 'have to see them in a bar' list. I've seen King's X multiple times in all sorts of settings and was spot-on with THAT call... so I'm guessing Clutch would be the cat's ass close up with booze.