Regular Endings (top)
These can be obtained with any game, by completing (or failing to complete) specific tasks. The chart below defines the endings and lists their objectives. Below are explanations on how to meet those objectives.
Bad
Bad+
Good
Good+
Save Cybil
No
Yes
No
Yes
Motorcycle
No
No
Yes
Yes
How to Save Cybil Simply get the Plastic Bottle in the Kitchen of the normal hospital and use it to pick up some of the Strange Liquid on the floor in the Director's Office. Use this on Cybil during the fight with her at the amusement park.
How to Uncover the Red Vial in the Motorcycle In short, do not proceed to the lake right after exiting the sewers, but rather head to Annie's Bar. Use what you find there to make your way to a motorcycle and open it. Use the "Resort Area" section of the walkthrough on this site for details.
UFO Ending (top) This is a special ending obtained by playing through Next Fear Mode. After beating the Good+ ending (above), an item called the Channeling Stone will become available in the Convenience Store in Old Silent Hill on your next round through the game. It must be used in five different places, and at the fifth place, the ending will occur. After this, your next round in Next Fear Mode will feature the Hyper Blaster weapon, which will automatically be in Harry's inventory at the beginning.
The Five Locations to Use the Channeling Stone
Roof of the Alternate School
Courtyard of the Hospital (right before engaging the Moth)
Parking Lot of Norman's Motel
Inside the Boat
Roof of the Lighthouse
The Rumored 6th Ending (top)
If you've been around the block on Silent Hill message boards, you've probably heard of this at one point or another. It should be forewarned that the idea is completely false, and this has been proven by countless failed attempts and thorough analysis of the disk. Still, it makes for a good bedtime story.
The supposed procedure for obtaining this ending is as follows. In some subsequent Next Fear round of the game, Harry will be able to pick up the Glucose and the Distilled Water from the school's lab storage. He will somehow use these to make a bomb and blow open a door in the hospital, leading to the ambulance parking lot. The engine sitting in the gas station, along with the gasoline, can be used to mobilize one of the ambulances, and Harry will be able to drive it around. Crashing through one of the buildings in Central Silent Hill, he will a find a Boat Key, which can be used later on to access the boat in the Resort Area, which can be taken to a beach to obtain some heavy-duty White Claudia growing there. Finally, the boat can be used again to reach an island on which stands Dahlia's house, where Harry can perform a ritual at the altar (like the one on the third floor in Nowhere) and dispel all the evil that has engulfed the town.
This is evidently a fabrication, obviously for reasons such that (a) I'd sure like to know how to make a bomb out of sugar and water, and (b) we know that Dahlia's house is in Central Silent Hill, not on some island in the lake.
For a while, this story was very compelling, however, because of the peculiarity of the items around which it revolves. The glucose and the boat wheel, to name a couple examples, give a message when examined that implies "Come back later." The truth is that these features of the environment were probably part of Silent Hill's second scenario, starring Cybil, that we know to have been scrapped before the final release. These items are all clues to that lost scenario, and it would seem that whoever came up with the story of the sixth ending was at least smart enough to use them.
Below is a rather amusing impression of what it may have looked like. (Parts at the end are actually ripped from Silent Hill 4: The Room.)