This is something I suggest every gamer should do.
In this generation, I'm mostly playing shooter games. It doesn't matter how great Gears of War, Halo, Call of Duty, and other games are, even though I can play them over and over, sometimes you just want to play something different. I'm not saying different like getting Dark Sector, Army of Two, or other shooter games, mostly because even though they are different, they are shooters at their core.
What you should do, is create a little completly different game genre list for the days when you get bored. Who hasn't felt the need to play something but when looked around the games you have, you didn't feel like playing any of those?
Check my gamertag or my game collection (here in gamespot, it's updated) to see how many shooters I'm playing lately, and how some of the games I have are completly different.
Examples of different games that I play when I'm bored: Ace Combat 6, Burnout Paradise, Geometry Wars, Castle Crashers, Fallout 3...
It's always good to leave the routine, I always had this pile, and always kep my interest in videogames, the only difference is what was my main game genre in each generation.
PSone -> RPGs was my main pile
PS2 -> Action Adventure
Xbox 360 -> Shooters
Get out of your traditional games once in a while, in order to broaden your horizons, keep things interesting, and keep the flame of gaming burning inside your heart.