Michael Richards (Cosmo Kramer) was an actor that was absolutely devoted to his character/job! I actually disliked the character "Newman" (Knight)... I mean he just never hit me right (I tried to force the fit, but he never quite did it for me!) Take a stroll through the bloopers/Gag-reels on YouTube, and there's even some that are just devoted to each character - watch the Richards (Kramer) one, and you'll see what I mean! I mean he was funny on set, but the guy was serious and once he was in character, he was in it to win it! Newman... Blah! Gave me a chance to grab a snack when he came on set! LOL!
Hhaa lol its tough but Id go with Newman he had been in really funny skits as well from other shows I suggest you watch him in this episode from Becker called "picture imperfect" season 4 episode 17. Its hilarious plus I like how his character is always protereyed as the guy who goes crazy over the littlest things.
Kramer Crazy girl I am, @Afro-dite9 However, I did Love All of the Characters in Seinfeld, no doubt about it. Problem is though, I didn't care for Any of them in their Own Shows when their own Show Goes. "Old Christine" is the Only one that made it. Good luck and Great question. xx