The original is obviously the best, after that the 3rd film does have a lot more originality to it but honestly I do have to say I still preffer the 2nd even if its rehashing the original formula. 1990 really was the year of the underrated action sequel for me with Die Hard, Predator and Robocop 2 coming out, all very enjoyable, none of them with a great rep.
After that I feel its a steep dropoff, the 4th film wasn't bad I spose but didn't really have much to recommend it beyond any number of standard action films from the era, the 5th wasn't very good at all to put it mildly.