There are some good ones here that I had completely forgotten about. Hot Shots and Gremlins are two sequels that are as good as the originals in there on way if you ask me.

Sadly I found Airplane 2 to be dull except for Shatner's bit.

Ghostbusters 2 just felt like a depressing retread of the first film that undid the happy ending of that one. I really don't want my comedies to depress me and that is what the opening of Ghostbusters 2 does every time I watch it so I just avoid it these days.