@ Kuma
I actually thought Tabuu was a solid boss. Not as good as Giga Bowser or Crazy Hand (although more unique), but entertaining. I felt that super kill move was stupid though. Also, his boss stage should have been like a climbing one (like Infinite Glacier, but slower, and with only platforms like ones on Battlefield).
The other original bosses IMO sucked in Brawl.
-Rayquaza was great, although he could have used an extra attack and like a hyper strength boost.
-Petey Piranha was too easy. It should have had at least two more moves and should have had like a super fire attack or something.
-Porkey's chase scene should have had more up and down dynamics. As for the boss fight, it should have been in stages. Like if Porkey's spider machine broke, and he had to have a smaller robot with less health but more power fight you.
-Ridley should have had a few unexpected tricks. Oh and more long-range attacks by Ridley. Perhaps change it to Omega Ridley.
-Meta Ridley's boss fight should have switched between an open area, tight tubes (that Meta Ridley could combo you on), and perhaps force the fighter to switch ships they are on; it could be like fighting on Big Blue!