Sir Daniel's best is definitely Franzea. Worst is probably Dojo, since it's so hard to rack up level one kills there, and the level two becomes almost useless after the walls disappear.
PaRappa's best is Alden's Tower. So many walls and there's a pit at the top where you can smack people in to for free kills. His worst is Sandover Village. No walls.
For Sweet Tooth's best stage I'd go with San Francisco. It's not so big you have to spend precious seconds trudging back to the fight, there's several perches to get and stay above your enemy, it has a thin platform to surprise people with the missile (if absolutely necessary, it has three platoes too small to avoid mines, and lastly it is perfect for his level 3. Get to the left and there's no hiding places from the gatling gun, and there's the thin platform that tempts foes into rocket territory or can be used to stomp a wide shockwave downward.
Worst stage for him has got to be The Garden. It's way to big for him to traverse quickly and has so many platforms, it makes it hard to utilize mines or the gatling gun.
P.S. The best stage for his LVL3 alone, I think, is Sandover Village. Same benefits as San Francisco but with the added benefit of water.
Cole (at least for me)
- bad: any stage with too many platforms, such as Time Station or Paris (I love the homming rocket for dealing with zoners, and these levels suck for that)
- good: every other stage, though San Francisco and Stoaways are my best