re: If Serena the greatest female athlete of all time?

Maybe the greatest tennis player, but not "athlete".

as far as Graf beating her, it's hard to say. Graf had that defensive backhand, which she had very few unforced errors with. As any sport, it's hard to compare past and current players. Not to mention the racquets have changed quite a bit since her career peak...

I've never liked Serena, such a bad attitude. I respect her game though.