123. 
That is the amount of "common" achievements I have yet to obtain in my 360 games.  If you are like me, then you love collecting achievements. I think they are great; they give me incentive to play games in ways I would never imagine playing. They also give me a chance to test my skill with my games. Some are really hard. Some are really easy. Those green achievements I see here on Giantbomb, I like to call those the "easy" achievements. Giantbomb lists them as common because, well, everybody has them. You're nothing special if you have those achievements. In fact, you're less than special if you don't have them. 
So in my endless quest of achievement hunting, I will go after all of the common achievements I don't have.  Here are the games, and the number of "easy" achievements I've failed to get:
 
Elder Scrolls: Oblivion (41) 
Street Fighter IV (8) 
Green Day Rock Band (8) 
Rock Band (1) 
Guitar hero II (5) 
LEGO Rock Band (7) 
Mass Effect (4) 
Geometry Wars 2 (10) 
The Misadventures of P.B. Winterbottom (6) 
Sonic the Hedgehog (3) 
Castlevania SOTN (2) 
Defense Grid (2) 
Sonic the Hedgehog 2 (4) 
Sonic the Hedgehog 3 (12) 
Sonic & Knuckles (10) 
  
123. That's a pretty intimidating number. Something tells me, this probably won't be so easy...     
 
What do you think? Care to join me on this challenge and go after your own common 'chievos?  

Already got them all, and looking to get those uncommon and rare ones out of the way?  

Any other achievement challenge ideas you can come up with? Share them with me!  

Think I'm crazy? Aren't we all? ;-)