Axel's ending in Head-On; a mad scientist bound him to his old car, and forced him to enter Twisted Metal as payback for replacing the arms and legs Axel tore off in his ending in II. Axel was supposed to give his wish to the scientist, but after seeing all of the death and destruction caused by the contest, decides against it. Realizing what's happening, Dr. Zeemu shocks Axel, causing his wish to come out as, "I wish for Peace-AHHH!"
Shadow's ending in Head-On. One of the few times Calypso doesn't even try to screw over the winner for once (though he did try to suggest Mortimer to wish for killing the kids who woke him up), he actually complies with Mortimer's request and sends him back to sleep in his grave. How, you ask? By reading him a bedtime story about his victory while he's lying in his coffin with a teddy bear, complete with kindergarten-style crayon drawings!