Jojo never really had fights from what I've seen, at least not in the same sense of One Piece. It's usually just one challenge presented to Jojo's group, and they must overcome it. I don't remember everything I've read though, and I only read up to volume 5.
However One Piece has the best fights I've seen. Sanji VS Bon Clay still reigns #1 on my Top 5 Fights list. It's a fight where it's pure action, and when they stand on their hands and start kicking, it's just like, "Oh hell yeah!".
Oda also mixes up humor into his fights well. Tons of times character's will performs stupid, or ridiculous moves just to make you laugh. Kaku's whole fight was full of them. The pasta machine and the square move come to mind. Oda just has very innovative and new ideas. Is he the most original? From what I've read, yes. He makes fights even sided most times, or makes them interesting. Nami VS DoubleFinger wasn't very even sided, but it was still an amazing fight. I haven't read every story with fights ever though, so perhaps Oda isn't the most innovative and original. Still, Okama Kempo, Coop de Poo, Giraffe Man, Three Sword Style, Soap Woman, and Cloud Sword are some of the most interesting, hilarious, and well done ideas I've ever seen.