In terms of fame, we could call him Casey Affleck. He was well known, but his brother Edwin Boothe was way more famous. In terms of talent, though, Edwin was considered one of the greatest American actors of his day, and I don't know if we can say the same about Ben.
fyi, there was some good info on John Wilkes Booth a few months ago - check it out
In terms of a ladies man/heartthrob though, where would he fit?
I just noticed coincidentally that Terry Alford, author of a new biography of John Wilkes Booth, is doing an AMA if anybody's interested. Maybe we can ask him the same question and see how his answer differs :)