Game design is an iterative process, which is to say everyone rips everyone off. Don't believe us? Play a shooter after 2007 that didn't have Gears of War's cover system and Call of Duty's leveling. Other times, developers seemingly ignore amazing ideas. Like Shadow of the Colossus--the fact that more games don't involve climbing giants is shocking to us.
We're going to have to go with Eternal Darkness. The Sanity Meter and Sanity Effects should have become a staple of horror games after Silicon Knights pretended to unplug our controller and faked a blue screen of death. Instead, they're forced to live a life in purgatory as Denis Dyack continues to try and fail to Kickstart a spiritual successor to the cult classic. Maybe that's the best Insanity Effect.