8 and 7 are probably the least hated, but 3 and 5 are pretty popular too. some people swear that part 4 is the best, but I also know a lot of people don't like 4, so that one's very divisive.
parts 1, 2, and 6 are all alright, but they have their problems. 1 and 2 are mostly just kinda dated and simplistic, and 6 is a bit out there... I think it gets a lot of unnecessary hate, but it is a bit of a jumbled mess.
I think 3 is traditionally the most popular part, but most people will probably say Part 5 is the best right now because of the anime. Either 7 or 8 are objectively the best though, but they havent been animated, so theyre less popular