Halo is more skillful than CoD, but I've never played Gears so I can't comment. CoD literally requires no skill, the maps are so complicated (there's so many small buildings with tons windows and corners) that people just crouch in the corner and spray their 0.5 sec killtime weapon at anyone that runs past. Srsly. One time, I went over to my friends house and played him 1v1 in WaW on his PS3. It was my first time using the console and playing a CoD game and my friend played it pretty regularly, yet I beat him like 25-19. There's no way I should be able to pull that off on my first time, an he was pretty decent at the game too.