It's exactly the other way around for me.
I know the sequel is beloved and it opens up the world and does something new with the material, which I applaud, but I never found it nearly as interesting as the first one, which is a true gem and has a better storyline. Pitch black psycho-sexual horror about flesh and soul.
I also feel that the Cenobites are more intriguing as background players, and I prefer the mystique which surrounds them in the original.
Part 2 is more of a footnote for me. It's okay, but not really necessary and not as interesting.