I've always been a big fan of Marshall 4x12 cabs (the real ones, not shitty ones - I use a 1960A or something). Mesa and Bogner cabs are really good as well. If you want to go trve kvlt metal you could get a Vader, but I always thought they looked tacky. Splawn cabs are really great too.
Any time I've ever shopped for a cab I bring my head with me and try it out on them. Just make sure you know what speakers it has in it. I've probably owned like 10 4x12 cabs but I always go back to Marshall.
Edit: Finally got the OK to buy a new amp. I sold all of my amps about 7 years ago to fund school while working a shitty job. I've owned Engls (Fireball 60, Powerball v2, Blackmore), Mesa (Mark IV, Triple Rectifier), Marshall (DSL, TSL), Peavey (5150!!!), VHT (2/90/2), etc. Not 100% sure what I want to get yet but I'm leaning towards a Fireball 100 or a good ol' Peavey 5150. Plus side of the 5150 is you can get them for like $600. Plus side of the Fireball is it will give you the biggest pair of balls in the world. Not sure.. Price difference is about $1200, for a used fireball maybe $700 difference.
Double Edit: If you buy a brand new cab, you'll need to break it in. A lot of guys will put the cab face down on their mattress and setup their guitar in a way that it just keeps playing feedback through the speaker. I forget how many hours you need to do it but I remember new cabs sound really stale until you break them in.