Games You Play In & Peruse (and notifications)
There's a little minus sign in a box next to each entry on that list. Click on the sign, it removes the game from your list until such time as you get a notification from the game (if you're not actually in the game, it goes away until you get a PM because you were added to it).
It's also a good way to clean up your list if you have inactive games that may revive...take 'em off the list, and if/when someone posts, it will pop back up.