I have to nominate my fav, Patty. Her last two boyfriends have both been sentenced to jail terms, which I'd say is a darn good start towards building Tonya Harding credentials. Plus, before her current thug of a boyfriend (if you've ever seen the guy you know what I'm talking about) got his ass nailed by the German feds, he provided the key evidence that got the first boyfriend locked up.
Patty breaks her rackets on court, hits balls at the crowd, and curses violently in German at umpires, opponents, and fans. That's why I'm a big fan of her, and I think she's a strong contender for the esteemed Tonya title. All we need is for Patty to set up her arch-rival Anna K with a harmless little "accident," like setting her hair on fire in the players lounge, and we'll be good to go.