In most non-X-men forums Gambit would win this instantly, however there have been so many bad X-men accents, due to the X-men's approach of giving us heroes who may not have come from the mainland UK/USA what is the one that has made you laugh out loud?
Gambit: May as well lead with the ridiculousness that is most famous for bringing the X-books down. Gambit has a New Orleans/French accent that makes no sense and inspired Fantomex which alone deserves him a place on any worst ever list. https://www.youtube.com/watch?v=tYscJKMpN2E
Wolfsbane: Lots of Ah'm and dropping the last consonant of words. No Scottish person I've ever know talks this way and half my family is Scottish and lived up there many years. Pretty damn shameful.
Rouge: As much as she is a fan favourite she sounds moronic and could never be taken seriously saying things like this: https://www.youtube.com/watch?v=ujPF9k1llZA
Cannonball: Supposed to be the leader of the next generation of X-men, yet sounds like a hick who's never seen the big city whenever he appears, time to put this redneck down.