Thanks for making this thread!
I'm quite fond of this series, and I think it has the best fight scenes of any manga I've read, particularly its emphasis on clever tactics and applications of powers.
Even though this series is popular and influential within Japan (quite a few fighting game characters are inspired by Jojo's cast) A lot of anime/manga fans I've met don't seem to know about this series probably because of its age, the fact that only part 3 was licensed, and the lack of any strong anime adaptations and I would love to see a good anime adaptation of this series. I can imagine how awesome some scenes like the motorcycle chase in part 4 would look animated, and it's already awesome in the manga.
Haven't finished Steel Ball Run yet and I can't read Japanese so I'll have to wait for people to finish translating it, but I enjoy it a lot so far.