Seinfeldisms and original quotes are always classic!
She has "man-hands"
He's a close talker
He's a gift-recycler!
"You heard I was in the hospital and decided to stop for a box of juji fruits?!?"
Or when the George doppelganger, Neil, in the hospital laughs at George for attempting to out-Neil him by taking his chick. The evil Kramer double is hilarious too (when Jerry has his own show). The mannequin in the clothing store that looks like Elaine. The doll that looks like George's mother.
Kramer and the way his hair ripples and waves along with his forehead when he slides into Jerry's apartment..."Hey, Jerry"