Definitely The Watcher in the Woods
for me. Granted, I was young at the time, so it may not have the same effect. But I'd rather remember it as I have all these years... ****ing terrifying.
Not in as I already have AitD and Undying. Despite my fond, if frustrating, memories of Sanitarium, I'd rather not enter for one game when someone else could benefit from all three.
When you redeem a code, only the games you already have are added to your account. Those you don't remain in the code, and can be redeemed by someone else .