How bad are M rated video games?

This time of year, many parents purchase video games for their children. Frequently, they ignore the M rating (similar to a movie's R rating) - after all, how bad can they be? Well, as a gamer, I want to let you know exactly what your child(ren) is getting when they talk you into purchasing that game. All M rated games contain material that few parents would want to expose their children to; however, I cannot post excerpts from all the games. Instead, I am posting videos from youtube of gamers playing some of the more common ones. These will give you an idea of what you can expect.

At the same time, when you click on these videos, expect to see graphic depictions of violence, nudity, and sex as well as inappropriate language. (Not to mention immature gamers commenting in the background - comments you can expect your kid to be hearing if they play online or interactively - after all these are the people they will be playing with.) Please note, you may need to watch these at least 5 minutes each because some have only mildly offensive material in the first minutes. Keep in mind, though, that you kids will be playing these for hours, often repeating the same scenes over and over again as the master it:
Assassin's Creed:

(Assassin's Creed always likes to throw in a little sex, too:)

Saints Row:

Grand Theft Auto V:

Far Cry (not the only graphic sex scene in this one):