When something's good, I never want it to end. In t.v, the fact that Chuck ended after 5 seasons was absolutely gutting, particularly as only two seasons were full 20+ ones (I also hate how in England we have 6-episode series. Skins seemed long because they did 10/11 episodes per series). But then again, I used to read Hayate No Gotoku! (Think that's what it was called) manga on the internet, and there were so many chapters and so many similar-looking girls who were into him at one point or another, i just got confused and stopped reading.
I don't mind long films, provided there's enough plot development or action scenes. For example with the Dark Knight Rises I get over the lack of action by the fact that the talking, and even the silent bits, are so good. But with the Fast and Furious series I'm glad they're bringing more action into it - there wasn't enough racing in the early ones, although they were good. (The effects were shocking too, just watch the main drag races in TFatF and 2F2F again, when they use Nos it's hilarious xD ).