I LOVE, LOVE, LOVE my Classic 30.
I've got a Celestion G12H30 in the amp, and a Celestion Greenback in a 112 extension cab. I think I've got EH 12AX7s and JJ EL84s in mine.
Honestly, the tubes matter less than the speaker. The Celestion made a world of difference to the tone of the amp, and it sounded pretty damned good with stock speaker.
I've had mine for at least 10 years now. Got it at a pawn shop for $200. It has broken down on my once...bad solder joint, but a local amp tech/friend of a friend fixed it for free.