I just got my new Ear Candy Sovereign 1x12 cab. I put a Celestion Sidewinder in it. What an amazing sound! If you don't know about Ear Candy you should check out their web site (
http://www.earcandycabs.com/). I have never heard such a great sound from just changing the cab. I plugged in my McIntyre Bluesmaker with my 54 LP and the sound from the P-90's was awesome.
The workmanship is also incredible, they cover the cabs in elephant grain tolex in any style you like. They claim that their 1x12 Sovereign can beat any 2x12 and even some 4x12's and now I know why! The guy who owns the company is a fanatic about tone and gets his woods made specially. Interestingly, his name is also Tim!!
I already have 2 other cabs on order, one is a 1x15 for my bass (this will also get a Sidewinder), and the other is a custom build head and 2x10 cab for my 8 watt class A amp. The 2x10 will use an Eminence Ramrod and Lil' Buddy.
I'm already thinking of selling my Avatar 2x12 so I can get a Buzz Bomb!!
The picture was before I put the speaker in, but it lets you see the quality.