A lot to comment on here...

Firstly, I think The Godfather Part II is slightly better than the original, though I'll concede it is more study of power and corruption than gangster film. I offer a more robust defence of the film here, if you're interested:

https://fanfare.pub/the-godfather-part-ii-the-greatest-sequel-ever-made-50728e0d8f1d

Terminator 2 is brilliant, but I still prefer the first one. I like the love story element, the tightness of the script, and the stronger horror element amid the action.

The sequels listed here are simply my ten favourite sequels, per the criteria I outlined at the start. Some are better than the original, some as good as, and some perhaps not quite as good as but still worthwhile. It's simply my opinion. Other opinions are available. :)

My thoughts on Superman II are here (I prefer the first film, but still enjoy it a great deal):

https://fanfare.pub/superman-ii-the-dillon-empire-edit-1a6e515bab49

Batman Returns is an excellent shout, I agree. My favourite of the two Tim Burton Batmans.

I'm not a fan of any of The Matrix sequels (scroll down into this article to see why):

https://fanfare.pub/ten-sequels-that-disgraced-their-parents-ddaef3b1429a

The Color of Money is a fine film in its own right, but I prefer the original (The Hustler), which is a classic. :)