That guy in Ace Ventura is Jim Carrey.
Have you seen Eternal Sunshine of a Spotless Mind, The Truman Show or The Number 23? Not exactly slapstick.
Just because movies are based in the same time period, doesn't mean the roles are the same. Elizabeth Bennet is nothing like Georgiana, the Duchess of Devonshire. As for Lizzie Bennet, she did that back to back (by that I mean she had only days between filming) with Domino. Hardly similar.
Her character in Atonement is a wealthy socialite whose one true love is separated from her by the cruelty of fate. From what I gather, her character in The Edge of Love is a hedonistic, bisexual woman who sleeps with her first love and his wife.
I think a lot of people get this notion of her playing the same role over and over because of The Pirates of the Caribbean trilogy. When you examine the actual roles she's played, very few of them have been all that similar.
"Purgatory's kind of like the in-betweeny one. You weren't really shit, but you weren't all that great either. Like Tottenham."
I'll try being nicer...if you'll try being smarter.