About Terminator. I reaaaaally liked T2 when I was a kid. And I was sorely disappointed with t3 when it came out. But I rewatched them all after becoming obsessed with the Sarah Connor Chronicles and . . . T1 is actually much better than T2 to me now.
But I actually prefer the TV show. No Arnold! Yay! Hotter John Connor. Yay!
As for other sequels that are better than their originals . . . Revenge of Madame Doubtfire. It was so hilarious seeing Robin Williams as an old English lady in the Iraq War. Priceless.