Jeez, talk about a tough question. That's kinda like your point about hulls, and I'm spoiled because I get to most of the new stuff for a living and then write stories about 'em.
Pre-1970, call it pre-1968, I'd say any Triumph as long as the motor is built right and you're running an electronic ignition. Norton Commandos are pretty awesome, too. If you're talking 70s, that's when the Japanese really took over, so then it's Honda CB750s, Kawasaki KZ900s and Yamaha 250-400cc two-stroke twins. Then you get into the real superbike stuff from the 1980s on.
If we're talking dirtbikes, then CZs and Husqvarnas are my faves from the early '70s, and I dig any Husky from 1966 to 1988. After that, the Italians who owned Ducati bought them and screwed them up for 20 years. BMW bought them about three years ago, and their stuff is really good again.
Nowadays, it's Aprilias and BMWs for the street, and KTMs and Huskies for the dirt.
But one thing I learned too late over the past 20 years, it's that you should never turn your hobby into a profession because then it just becomes work. That's why I want a jet boat, to get away from bikes once in a while. Even if it's work, it'll still be fun.