Along the same lines as the Simpson personality types, what personality types do you think the characters of Seinfeld have?
Here is my take. One thing to be pointed out is that it's considerably harder to to discern introverted thinking in a tv show.
Jerry Seinfeld- INTJ (in real life, he is known to be serious and disciplined.)
Elaine Benes- ENFJ
George Costanza- ISTP (with uncomfortably forced extraversion in certain social situations)
Cosmo Kramer- INTP
Kramer is definitely an INTP. He is the quintesssential underachieving slacker who frequently develops crazy, yet logical ideas.