By gratuitous, it can be anything: violence, just plain gross, sexual, etc.

Some examples of blatantly gratuitous violence in the past would be the fatalities and in Mortal Kombat.

But today, I am going to have to go with the "Ramen Timer" in the PSP game "WTF - Work Time Fun" for gratuitous T&A.  It's video of a real life girl in a bikini (or a guy in swimtrunks) posing around for the several minutes it's supposed to take for ramen to become done.

The sex mini-game in God of War series lol

That's a good one.

The curb stomping in Gears of War, you gotta love it.

It's difficult to get a curb stomp! I shot a locust in his legs to make him go down, and then when I got to him, he had gotten up and he frickin clubbed me to death lol :(

 Learn2Play? LOL jk

Ouch, brotha!

Unfortunately, I don't have a 360, so whenever I get my hands on Gears of War, it's always in spurts and I have to get used to controlling it again. And my friend likes to play on Hardcore or Insane, so it isn't exactly a walk in the park :P

The three way girl action in FFX-2.

Knocking a cocky opponent off the stage in Super Smash Bros. Melee.

             I had the recent opportunity to play Gears of War, and the whole cutting people in half with a chain-saw