If any of you also attend the Something Awful messageboards, you'll know what a lets play thread is and more than likely what this site is.
For those who don't a Let's Play thread is a thread on the SA messageboards, where the OP plays through a game, recording his progress via screenshots or video uploaded to streaming sites and supplying a commentary at the same time, which is nearly always good for a great laugh.
On the link there's over 200 archived threads, displayed in nicely laid out web pages. It's always great for a laugh and also there's often some games on there you could never be bothered to play, so you might as well let someone else do it for you and crack a few jokes at the same time. It's updated regularly with new games and free. Personally I've spent a hell of a lot of time over there reading. I'd recommend the Resident Evil threads, Silent Hill threads, Mario 64 Thread, Dungeon Explorer Thread and the Half Life 2. Well theres tons of great ones on there.