You try not to get a boner in Cape Fear. But yes she's a stupid bitch, still one step down from Kirsten Dunst though.
There's Julia Roberts. Dunno about more annoying though. At that point, it's hard to distinguish between the varying degrees of annoyingness.
Natural Born Killers? The only thing that could make a serial killer couple, the male counterpart of which is played by Woody Harrelson more despicable and disgusting is to have the female counterpart played by Juliette Lewis.
All the actresses mentioned in this thread probably tie for the title. I'd also add Blake Lively but she's a different sort of annoying. She's more of a "holy fuck she is the worst actress in the history of filmmaking" annoying.
I'd still fuck the dogshit outta Kathy Griffin. Face ain't anything to look at but the chassis is pretty damn solid for a chick in her 40s.