You know those multiplayer games where the story involves a group of heroes- you, the single player, choose your single character out of the group, fight through each level all by yourself, defeat the boss all by yourself, and then those hosers show up out of nowhere and share the credit for your victory? The cutscenes make it look like the whole group is there, but it's really just your single character. I hate that. Especially the endings - "We finally did it , guys!" .. I'm like "We? Who the hell is we?!"
Off the top of my head, I can think of
Dungeons and Dragons arcade games
Final Fight game endings (I think...)
Streets of Rage III
Soul Calibur Legends
It seems like beat 'em ups do this more often than other games.
What else?