i'm breaking the rules and not classifying them*.
Ampeg - I love the Lee Jackson designed VL-1002 and 1001 (i think those are the right numbers)
Fender - The best amp they ever made was the Prosonic (IMHO of course) (my super60 rocks too!

)
Mesa boogie - 'nuf said
Vox - Can you think of a sweeter vintage tube sound? OH LORDIE!
Rivera - DROOOOOOOOOOOLX0000rz
*none of the amps mentioned involve solid state circuitry.