He might be at an awkward age where he considers himself 'too old' for stuff like Mario and Rayman (regardless of how difficult or good the games actually are), and wants to play the big name titles like CoD/Battlefield/GTA because they're so highly regarded by the gaming media (and so heavily hyped).
Racing games are normally a safe bet - the Gran Turismo, Forza, DiRT and GRID series are very good, and you can also pick up Blur and Split/Second at a bargain price now.
In terms of action games and shooters, it's probably worth bearing in mind that the age ratings are far harsher than they are for movies - what would be a 12 for a film would be a 15 for a game, and what would be a 15 would be an 18. There are some games that do thoroughly deserve their 18 rating though (GTAV - although you can run over a bike thief and return the bike to its rightful owner, so that's nice).
If you're OK with fantasy violence, Darksiders II is good fun - there's glorious, glorious decapitation and stabbing (you play as Death, in a 'one of the Four Horsemen' context), but you're fighting monsters rather than people, and it's very stylised.
Diablo 3 has just been released on the home consoles too.