Endings:
Maria (dont listen to hallway conversation)
Leave (inspect Mary's photo and letter multiple times + listen to full conversation)
Rebirth (pick up the book in the lost and found room and complete the game)
Dog ending (go to 3F then observation room and use the dog key)
UFO ending (go to 312 and instead of the video tape just inspect the gem in your inventory)
You will also get achievements for:
I saw that town
Faster than fog
Radio silence
As close as you like
I would like to find a way to edit my inventory/save so I can get the other endings.
Put this save in %LOCALAPPDATA%\SilentHill2\Saved\SaveGames\<user-id>\SaveGameData_9.sav