Insane, hardcore, hard, suicidal... Whatever the highest level of difficulty is in the game, that's where you'll find me.
Theres several reasons behind why I do this. First of all, not all of us can just simply "Move onto the next game." Money is funny, and these days she's tight.
I don't get any joy playing on easy mode. I end up plowing through a game in a very short amount of time and thus I end up feeling that I wasted $50/$60 dollars. I've also been playing video games since I was 4, so there would have to be a serious problem if there's a game I can't play on the highest difficulty.
That and I've noticed that I gather more attention from my non-gamer friends when I play on the highest difficulties. I love when people watch me play, and I've noticed that people love to watch me play when there's some form of suspense. A "What is going to happen next!" or "How will he get out of this jam!?" situation.
I remember reading or hearing some where that surgeons play video games to help improve their dexterity and reflex in there fingers. I have found that playing games helps improve your overall dexterity and reflex, not to mention if you play an FPS game the way you're SUPPOSED TOO, it also helps improve your hearing. Listening for those very small sounds in the area around me has made me aware of the lightest of noises, like this one time one of my lady friends was walking behind me and went to slap my ass and without looking behind me I put my hand there to deflect it because I could hear her hand passing through the air.
If you play RTS games like Starcraft on melee. "Melee is when you start off with one main building and a couple of workers and you have to build a base and an army and try to take over the map and destroy your opponent(s)." Playing these games helps improve your problem solving skills, for your opponent will constantly send problems your way and you must figure out a way to solve them as quickly as possible.
With these benefits to gaming, I often wonder why would anyone WANT to play on 'easy' mode when they consider themselves a regular gamer. If it's to enjoy the storyline, why not watch a movie instead? There you'll be able to enjoy the storyline on the easiest setting ever!
I have never found myself enjoying a games storyline any less due to it's difficulty... In fact, playing it on the hardest difficulties has made me appreciate the storyline a lot more because each piece of the story that I unlike feels extremely rewarding.