Lately I've been feeling really nostalgic about my old days in the Xbox 360 world. So I've reliving it a bit, bought a 360 and made some accounts.
One of the things that used to be popular was "game adding", it was just getting a select game on your "previously played" page, I'm not sure why it was so popular. Some people would take it a step further and add the the gamerscore for each game, that never really bothered me, I think it was more about the collection of the data.
So I've take it to the next level, I've made a dummy GPD file for every game currently listed on Xbox.com, and added them to an account. After a bit of syncing, and downloading I now have a profile with every Xbox 360 achievement. I published it.