8. Vin Diesel - The Pacifier (2005)
After the success of his first starring vehicle, the Fast & The Furious, Vin Diesel was poised at becoming one of the top action stars of the 21st Century. Then he decided to star in The Pacifier, a straight-laced Disney comedy, and he never really recovered. Playing an ex-Navy SEAL assigned to protect the children of a fallen SEAL, Diesel hams it up, dealing with cranky toddlers, a wacky Nanny and a horde of ninja assassins. This is the standard issue action comedy, put a tough guy in a room full of kids and hilarity should ensue. It worked 15 years ago with Kindergarten Cop, right? Sadly Diesel lacks the charm to pull off such a venture and he is left looking pretty silly in all the wrong ways. Had he attempted to try going outside his safe zone and limitations as an actor he might have been able to pull off starring in this comedy and maybe had a longer lasting career as a versatile leading man.