The 120 minutes (at least) where you are sitting with a mixed emotion of extreme visual entertainment and a serious WTF sensation.
Includes the majority (if not every) movie by Michael Bay.
Basically take any action scene and add extra explosions and big things killing each other in the most brutal way imaginable .. then add some more explosions .. after all that you add some more explosions .. Then an extremely hot babe .. Then more explosions and 120 mins (at least) later you have fully experienced an original Michael Baygasm.
P1: Dude I just saw Transformers 3.. It was the biggest Michael Baygasm I've ever seen.
P2: Dude i know .. WTF .. .. She was pretty fucking hot though huh ?!
P1: Explosions and stuff !! and fuck yea she was !!