I was so pissed in HIMYM's ending that now I can't even watch the show in reruns. The ending actually made me (beyond) angry; yes, I'm weird and okay with that.
X-Files
Outer Limits (original)
Frasier
MASH
Downton Abbey
Honorable mention: Fawlty Towers, Are You Being Served, Golden Girls, Roseanne, I Love Lucy (Top 10?)
So tough picking favorites!
1. Gilmore Girls
2. One Tree Hill
3. Veronica Mars
4. Buffy the Vampire Slayer
5. Grey's Anatomy
Honorable mentions: Daredevil, Desperate Housewives, The O.C. and especially Orphan Black (Seriously, the way Tatiana Maslany plays completely different characters you can barely tell it's the same actress. She's incredible and deserves all the awards.)
Sesame Street
Laverne and Shirley
Seinfeld
Mad Men
Star Trek Deep Space Nine
Love that you have Veronica Mars! I was so sad when it was cancelled after season 3!