All based on what I have watched so far. Give me some more recommendations if you can.
Lightweight: Sean Sherk
Welterweight: It's a toss-up between your man Nick Diaz & Georges St-Pierre
Middleweights: Karl Amoussou or Michael Bisping
Light Heavyweight: Randy Couture, Rashad Evans, favourite is possibly Lyoto Machida
Heavyweights: There's a lot who take my eye. Shane Del Rosario, Randy Couture again. I found myself watching a few Ricco Rodriguez matches. Frank Mir too.
'Cos I've been looking for myself, I'm only watching like, matches that a highly known about/popular. So, KW, if there's anymore suggestions? I'll go check them out.