I really think any Smurfs movie will default as the most terrible abomination within a list of similar options.
Although, if the Chipmunks was still popular that would dethrone the Smurfs.
Never saw any of them, voted Smurfs 2 under the assumption that a sequel to a movie about the Smurfs would be a steaming pile of shit.
I still hate Doucheton Kutcher though.