I grew up in the NES era, so being let down by the endings of a game was the norm. But the one game that pissed me off the most was Ikari Warriors. A shitty port of an excellent arcade game, it was a pretty balls-hard, top-down Rambo shooter.
After you struggle through stage and stage of endless enemies (IIRC, with a limited amount of continues) you are rewarded with this: