Which "Mature" titles are actually immature?

[MaxwellGT2000]

The Ghost of RubangB said:
An M does not mean that the game is mature, but means that the game is intended for a mature audience. Most M games are very immature. The most "mature" game of all time is hands down Brain Age.

There's nothing wrong with an M-rated game being really immature and stupid and full of tits, blood, naughty language, and explosions, but there's something wrong with immature gamers think that those games are the coolest around at the expense of amazing games of every other rating. The fact is, most of these M-rated games are targeted towards 12 year old boys who watch summer blockbuster action movies and wrestling and aren't paying attention to any political/moral/philosophical themes behind the violence.

Hell, I'm one of the few idiots who actually likes to play Manhunt, but I'm not for a single second going to pretend it's more "mature" than Tetris or Portal or SimCity.

 QFT, the main point I'm trying to make, people confuse M rating for actual maturity in the game itself.

 @Rocketpig, Ok RE series is debatable I think its fine cause it reminds me of the B rated horror movies I watch (story wise) but everything else doesn't seem over the top so it got on my immature list it fits horror in every sense.