The first time I remember absolutely losing my suspension of disbelief was at the end of the first Mission Impossible reboot where Tom Cruise puts an explosive on a helicopter he's hanging on the outside of that's flying behind a train through a tunnel, and the explosion completely destroys the helicopter and flings him onto the back of the train. Yeah, that helicopter (which probably couldn't be flying through a train tunnel to begin with) was made of far tougher material than Tom Cruise. Any explosion that destroyed it, would have turned him into a stain on the wall of the tunnel.