What works for me when I feel I'm in a rut is to play a game that doesn't take too long to complete. 10 hours or less usually does it. The reason I do this is because the story flows quickly and it gives me sense of accomplishment when I'm done with it.
You can check how long a game takes at
http://www.howlongtobeat.com/
But be warned: Pick something that is actually worth playing. It won't help if you grab a game that takes 5 hours but it is absolutely crap.
Many games get shot down in the reviews because they are too short. These are the rut-killers you are after.
Originally Posted by reedOsama
This advice is gonna seem a bit weird but when I'm in a rut I look for games with great soundtracks... I'm not sure why but maybe it's knowing that I'll get a shot of nostalgia some time in the future when I hear the soundtrack again (even once the graphics and gameplay have become dated) or being able to listen to the soundtrack whilst studying (making my studying feel like I'm playing a game)
