Unlocking achievements is a fun reminder of progress for some, or a cursing addiction worse than death itself for others. Either way, Microsoft has now made it just a little bit worse. The gamerscore rules have changed.
As of now, a single Xbox 360 retail release has a higher potential gamerscore than ever before. The maximum now, per game, is 1750 GS and eighty achievements for a full game.
The previous limit was 1250 that was set in 2007. Gamerscore for downloadable content is limited at 250 GS per quarter with that maximum of 1750 GS.
The only 1000 GS game I have is Avatar, and that was a cheap way to rack the points.