Quality not quantity people, always remember this.
Nobody thinks you are cool because you play any old crap to get the gamerscore.
Fill your gamercard with good, well chosen games.
I know plenty of people in the 50-60k range. They play any old nonsense, get half the achievements (the easy ones), then move on to something else.
1000\1000 on something like Street Fighter 4 (something I'm working on) would be a far more impressive achievement than 90k of Avatar: The Last Air Bender.
Just
IMHO of course.