7. The Dog Ending - Silent Hill 2
Never has a video game made me shriek with terror so often and then end in a manner that made me laugh so hard as Silent Hill 2 has. This game might well be the peak of psychological horror in video games as the finger on the pulse approach to scripting, enemy design and overall atmosphere are second to none.
However as you might expect from anyone who spends too long in the foggy town of Silent Hill, there's quite a lot of mad moments hidden throughout, but nothing as unexpectedly hilarious as the "Dog Ending" which you can get by either completing the game three times with the default ending or once with the much harder "Rebirth" ending.
It's worth the extra hours of work though because witnessing James Sunderland drop to his knees after realizing that all of the horrifying events he'd been experiencing were due to the actions of a dog operating a computer, is perfectly priceless.
Although the fact that the man is so distraught and it appears the dog attempts to feed on his tears does mean the comedy of the scene also carries with it some dark undertones. Seems like they've patched things up in the other comedy endings, however.