Hmmm... hard to pick, but... Cancer Bubble (actually, he isn't that great in-game, but he's awesome in the game-based anime) Doofensmirtz (Yeah, he's from TV, but he appeared in some P&F games) Kaos (some good lines in both games, especially in the second after becoming a giant mecha and taking over an ancient army) Wheatley (and the rest of the robot Aperture gang) Pete (as in, from Kingdom Hearts. He just looks so stupid in 358/2 Days!) Trying to think of more.... Your list?