Seems like Octavia (sister of Octavian Augustus and wife to Marcus Antonius) would have a decent career in Hollywood today – though I still maintain she looks like Lorelai Gilmore.
For Julius Caesar, using the famous bust from Tusculum, I got 58% John Travolta, 62% Julian McMahon and 60% Tom Green. Heh. The MTV of the 1st century BC surely had a Caesar Show of its own.
Pompey looks like Mika Hakkinen and Rubens Barrichello, which only confirms my initial suspicions that he didn't belong with the rest of the bunch. Clearly not Hollywood material. Well, it's good to know he has a niche of his own after all, but I can't really picture him getting into an F1 vehicle.
I couldn't get anything for Cleopatra, since I don't have a decent image of her – not that there are many, anyway. I was thinking Barbara Streisand.