The Incredible Hulk (with Bill Bixby)
Little House on the Prairie
Alias--although I stopped paying attention towards the end.
24--I've watched it on DVD
I think I've seen every episode of Friends now, but possibly not, since I didn't watch the first few years and have only seen it in syndication.
I missed the birth of Anne and Al's baby on Homefront.
I missed the birth of Carol's twins on ER. It was on Thanksgiving night, and we were at some friend's house, and this was before we got our TiVo.