I have to admit, the final episode of Roseanne was a good one since Dan died and Roseanne was reminiscing about the good times with her family.

I remember the Cosby Show finale. While it wasn't sad or depressing, that final moment when Cliff and Clair danced their way out of the set was simple and classy. A perfect ending for a perfect couple.

Newhart's final scene with Suzanne Pleshette made me go "WHOA!".

Dawson's Creek. I don't need to get into it. I cried through the whole thing once Jen's heart condition was discovered.

My most favorite final episode belongs to 90210. Though it was predictable (how could you really end the show with David and Donna NOT getting married?), one couldn't help but feel a sense of completion when the show ended. I don't know, maybe it was because I was in that stage in my life. I still watch the tape every now and then and get misty eyed as David and Donna are reciting their vows.

As far as the worst goes, definitely Seinfeld. The retrospect they showed prior to the Finale was better than the actual Finale itself.

I can't think of any other really bad ones.