I've really been into the amp thing for a while ..... Worst amp #1 I had an 81 Fender 75 head that always sounded like it was sitting in a mud puddle buried under a pile of blankets. It was terrible. No dynamics, no nothing. I bought it used and was stuck with it. Even after swapping tubes, it still was a piece of crap. I played that thing for 2 years Worst amp # 2 Marshall JCM800 50 watt. This thing had the 6550s and sounded really thin. I put new tubes in, but no improvement. It finally degraded to sounding like a long distance overseas telephone call .... as far as frequency response goes. I ended up booting it out the door. Worst amp #3 Marshall JCM900 50W hi gain dual reverb. This amp sounded better than the JCM800, but it just didn't have any bass response. It too had the 6550 tubes. I could turn the bass control to 11, or until it snapped off and still .... no bass. I kicked it out the door as well. Best amp #1 After the JCM900 disaster, I found a 1992 Mesa Dual Recto head. This baby was wrapped in pure leather and had tone controls that actually worked !! It sounded great! Sustain for days, all kinds of cool tones with this amp. Built like a tank too. I kept it for 10 years and it was a great amp for a hi gain type amp. No fizz like the current Mesas. Best amp #2 I found an original 74 Hiwatt DR103 and it just RIPS !! This amp sounds fantastic, especially with a P90 guitar and a TS808 plugged into it. It has such good definition that you can almost hear if you are playing with a Fender medium or one of those Green Dunlop picks ! 1! ! If you want to compare guitars or pickups, this is the amp to do it with. Best amp #3 Dr. Z Prescription. I am going to cram the original along with the newer ES version (EF86) front-end amp here. Can I do that? Both amps are non master 45 watt EL84 amps. The regular has the standard 12AX7 front-end and more of a British flavor. It breaks up into a nice warm crunch and puts out a LOUD 45 Watts. It too is transparent like the Hiwatt and sounds great with an overdrive pedal and a touch of delay. The ES model has more headroom and sounds Voxy in some ways and Marshally in others. It definitely has it's own thing going. Nice FAT bass response. The only overdrive pedals that I found will pass the full freqency response are the Xotic pedals.... the BB and RC work great with this amp. ... there are more favorites, but I didn't want to have to write a book about it !!