Okay. Coming from an admittedly small sample size of Fantasy, Sensation, Paradise, and Victory (Radiance, whatever), for my wife and I, it's Victory/Radiance.
Its not that it was a bad cruise so to speak, but there were warts. That was our first non-Fantasy class ship, and maybe our hopes were a little high. My thoughts are that some of the walkway designs were entirely too small (between pool area and buffet - I had to weave between people to pass through. I'd like to just walk around some). I dunno, there were some staff that were just incredible, but it seemed like we had a higher number of bored-acting crew than normal. And it really does seem like there's a lot more officers wandering around in guest areas, not that that's bad.
Our best cruise was on Paradise a couple of years ago. Everything about that trip (with the exception of the snooty bartender in the casino lounge that did NOT get a cash tip) was just perfect. I may never see him again, but Arturo, tending bar in the back of the buffet, was just the best, and I had a great time getting to know him.