Sequels aren't remakes, but they usually suffer from going downhill as well. I did like the first three Star Wars, back in the 70's and 80's. I think those three were all equally well done. I went to see The Phantom Menace. Not up to the previous standards. Then I also went to see Attack of the Clones. Another bad one IMHO. I have not seen any of the ones subsequent to that, but there have been a handful of them I think.
The original Jaws was superb. All the sequels have been quite bad in my view.
Crocodile Dundee, the original was fantastic, the sequels were a steady and rapid slide downhill.
Tremors - the original is still one of my favorites. The way Val and Earl play off of each other is mastery of casting, witty writing, and tongue-in-cheek performances. The second one was disappointing at first, but did start to grow on me a little, but still far below the original. After that, the rest of the sequels were bleuck.
Planet of the Apes. The original was good for its time, the sequels sucked. The remakes and more recent sequels are probably a step up from the original sequels, but not to the standard set by the very first one with Charlton Heston. Of course, I'd have to go back and re-watch the very first one again to be sure. I have a hunch I may not like it as much now as I remember from way back when.
One GOOD remake was The Parent Trap, IMHO. I liked the remake as much as the original. A great concept for a movie, and well done in both iterations.