So, as most people know, I am obssessed with
Xbox 360 Achievement points:
As anyone who is similarly addicted to improving their Gamerscore, there comes a point where one has to decide whether or not serious "boosting" (that is, really cheesy behavior just to improve one's Gamerscore) is called for. I decided to take a look as to how easy this is without actually taking the step (for now). What resulted? A little Google auto complete-like humor:

But enough about that. This is what I found:
1. Easiest 1000GIf you want both to get a lot of points
and get 100% of the points in that game,
Avatar: The Last Airbender - The Burning Earth is that game. AtBE has the somewhat dubious distinction of being able to earn all 1000G in five achievements
in about 5 minutes.
2. A Quick 6000GGamespot has a pretty good and
quick guide to do this. The quick summary: you can rent these (mostly EA sports) games and boost your score quite a bit and quickly.
3. More Recent List of Easy Achievement Boosting GamesA quick and easy list of games to get 100% of the achievements in can be found
here. Notice how three of games are FIFA soccer games? Five more are sports related. Makes you wonder about how much thought is put into these games beyond the sports action; but I suppose that's not surprising given how a sequel is made every year in a particular (mostly EA... did I say that already?) sport franchise. I mean, you have to get capture all the the new changes, right...?
4. The 10 Xbox Live Achievement CommandmentsThis
one really isn't about boosting, but I thought it was kind of funny.