Please keep in mind that not every member has finished all of the games, and some do mind spoilers! If you create a thread that may contain big spoilers, please mark it in the title so other members will know to stay away if they haven't gotten to that point in the game.
There is also a nifty code that ProBoards has for this exact issue in posts: [spoiler*]words here[/spoiler*] works wonderfully (without the asterisks, of course).