The Simpsons; I got all of them in my first account until it got banned. It's extremely cheap because it's old. Also, you get achievements for pressing start; playing for an hour etc.. TNA Impact aswell
Warface is easy to boost for them. I would go to gamestop and look at old games for $5 and look on the back they say whether they have achievements pick up Avatar the Game its suppose to be very easy to complete.