All the albums with tones I love are 5150's. I've tried a few ENGL's out through an ENGL 4x12 like 5 years back, and I honestly thought the Fireball sounded better than the Powerball, Powerball was all fizz, the Fireball was a fuckload tighter, and didn't come far off the Master Of Puppets tone that I adored back then. I'm not trying to say I'm an amp connoisseur or anything, but I just happen to like both the tones of 5150/6505's and Mesa Recto's more than anything else (although the Mesa tones have to have a decent amount of mids in them).
This is not meant to be a competition as I'm sure most of you guys have tried way more amps than me, but just so you know what amps I've tried, off the top of my head:-
ENGL Powerball/Fireball, Peavey 6505/6505+/JSX, Mesa Triple/Dual Recto/Mark I/Mark IIC+/Mark III, VHT Pitbull Ultra Lead, Krank Rev, Krankenstein, Hughes & Kettner Triamp/Warp Factor, B-52 AT-100, Marshall JCM800/JCM900, Various Crate/Laney/Marshall Valvestate/Solid State amps. And still prefer the Peavey/Mesa Recto tones more than any other amps, although the VHT wasn't far off either.