Don't know which aliens were running around in Greece & Rome.
They were Goa'ulds too. We meet Athena and Cronus in the series. Cronus was the system lord that killed Teal'c's dad and then died at the SGC when he was there for the protected planets treaty negotiation w/ Thor. Athena was the one that had Vala kidnapped in the one where she lost her memory and ended up working at a diner, she showed up somewhere else in season 10 too, I think. Then there was that one planet where O'Neill got him some alien puntang and got really old really fast. That place was run by a Greek Goa'uld but we never saw him, I forgot his name.
I voted for Ba'al. He's funny and the most humanesque of them all, the kind of guy that would be really fun to hang out at the bar with, assuming you could trust him not to try and take over the galaxy for a few hours.