I could forgive the film a little if there was something clever to latch on to, but there just isn't. The characters are pretty two-dimensional, the superhero fights are terrible and there's no world-building to speak of. Jesus, can I say anything nice about this film? The costumes for "G-Girl" (ugh, bad) are uninteresting, but at least she has her limbs covered? The powers are generic and only really play a role in jocular sex scenes and the idiotic "revenge" sequences. There is only one element of this film that is at all redeemable and that is the villain, played by Eddie Izzard.
Eddie Izzard should play villains more often. I can't even remember his character's name, but he ate the scenery and dominated the scene any time he was on screen. Disappointingly, his motivation turns out to be a high school crush, but watching, I really got the feeling that he was more than a match for anything that was thrown at him. He's not just several moves ahead, he's playing an entirely different game and you've already lost. I really want to see Izzard play a villain in a less comical film, someone like Purple Man, Lex Luthor or Vandal Savage. I cannot recommend My Super Ex-Girlfriend as a film to watch, even on the strength of Izzard's performance, just skip it and spend the time painting minis or something.