1. Season finale of Dexter. (I'm a lumberjack!)
2. Season 8 of Dexter.
3. Actually, anything after season 4.
4. True Blood, final season.
5. Heroes; season finale (S1) and everything after.
6. Roseanne- winning the lottery, because that's what made the show good, you know, money.
7. X-Files- all those great episodes after Duchovny left.
8. Scrubs- did you know that they recast the whole thing for a season? Yeah, bet you didn't.
9. Earth: Final Conflict- S1 finale, everything after.*
10. How do you spell the Office without Michael Scott? S. U. C. K.
11. Weeds- somewhere around S4 or 5 maybe? It lasted eight (8!) increasingly bad seasons.
12. How I Met Your Mother- Never watched it, but I'm told I never should. Something about the last episode?
13. Happy Days- have you ever heard of the phrase "Jumping the Shark?" Thought so.
14. Prison Break- What happens if you have a great concept, and you finish it, but you have to keep making episodes?
15. Grey's Anatomy- SPOILER! This show is still on. I know!
That's 15 quick ones. But if this is the most disappointed you've been in TV .... you've either live a charmed life, or enjoy the hyperbole.
*You can use this as a stand-in for countless Scifi and/or fantasy shows that have had a decent pilot or even season and then were absolutely destroyed by meddling.