Despite what everyone tells you, you'll never learn from your mistakes.
They always have pecans! (Read aloud)
3, duh. (My ex's 9 year old little sister told me this joke, and followed is up with: "and YOU'RE the math guy!" >< Burned.)
Ka-ta-na-na!
Bookkake
Gator-raid. <3 edit: Learned the difference between a crocodile and alligator.
Mothmatics!
Britney Spears
Because she had one heck of an ex-goose