They pretty much do since going for 1,000,000 achievement points pretty much takes up all of their gaming time.

Whoever retains the most retro fans from when games were more punishing, which merely levels the question of whether more long-term gamers have defected away from Nintendo than Nintendo has managed to retain.

Achievement points don't mean dick. It just means they buy every game the gets released. 

Judging by only those genres?

Sega gamers...

As a halo player, I believe I can kick your ass in only cs I own. :D

I don't buy into the retro = hard. The reason older games seem harder is because most of them had a limit on the amount of lives you had, which modern games obviously don't. And while old school games like Ghosts and Goblins and TMNT are very difficult modern games like Ninja Gaiden and STALKER keep that same level of challenge. And of course modern games add in complex PVP gameplay. High level starcraft play is certainly more difficult than any single player mode of any game of any era.

Well I used the most popular, but feel free to mention any other that I left out and how it can be judged and i would add them to the op

Probably Nintendo fans, they started out with much harder games (even if they were mostly platformers, rpg or fighters) than sony or microsoft. But i would like to say PC fans are better at shooters than the rest

Atari!