I'm actually starting out at the very beginning with the Phantom Blood arc, which is the one centered around Johnathan Joestar. Even at two episodes in, I'm really digging the overall feel, from its interesting color schemes to its visual style (which feels like it pulls more from manga than normal) to the personality of its characters.That's another one that's in the fourth season now, I think. Most will know it just for the Stardust Crusaders arc, which is what's airing now. The manga/show's story is told over centuries, each arc generally following a different generation of Joestar and Brando.
Also, I really like the opening theme for it.