Penis vs. Brain - The Nose Job - Season 3,
You are soooo good lookin' - The Good Sumaritan - Season 3
Kramer the Pimp - The Wigmaster - Season 6
Kramer the pimp is probably the funniest image from any Seinfeld episode, and the best line was quoted in "The Nose Job," "You're as pretty as any of them, you just need a nose job,"...to me it's more memorable than "Serenity Now!" or "Not that there's anything wrong with that!"