Full House series finale was the two part episode where Michelle lost her memory. Originally they were going to have one more season, but John Stamos didn't like the idea of moving to a younger network like the WB and the rest of the cast felt it was time to move on. That's why Full House's ending doesn't pop, because at the time of writing there was no solid plan that that was going to be the end. Other than the bit at the end where they talked about always overcoming obstacles.
I don't remember the ending of Fresh Prince either.
Agreed. I love Seinfeld and that ending was perfect.
Roseanne's ending still makes me O_O