My choice of cabs is a blend between two manufacturers:
I use a Rivera 4x12 on the top b/c it's very, very loud, very articulate, has great projection and resolution. It's also made out of very solid birch maple, and weighs a ton. The cabinet doesn't flex much when cranked, and thus you don't get much backwave from the cabinet itself in your tone.
I use an old (late 70's - early 80's) Hiwatt 4x12 for the bottom. It's an unbelievably articulate cabinet, and on it's own, it's a bit bass shy, but has a great midrange bite.
The combination of the two cabs is a very unique sound that I really enjoy!!
For live gigs, tho, I usually only bring the Rivera 4x12 for simplicity's sake.