My two favorite are Breaking Bad and Rosanne. Breaking Bad's tied up all of the loose ends and was exactly what I wanted to see happen.
A lot of people hated the finale to Rosanne but I thought that it was brilliant. It totally came out of no where and was such a downer. But it fit the overall show perfect. Especially the early episodes.
The Office Christmas Special
Six Feet Under's finale was master.
Rosanne's ending was rough. Cheers was good, too.
I would say NOT Seinfeld.
The Wire.
Futurama
Deadwood
You never even watched it you dick.
So? My experiment was a success.
;D