these days i tend to choose my difficulty based on achievements. if they require a certain difficulty, then I will play on harder settings. if not, i'll use easy to burn through it. after all, i am playing these single player games for the story, not to be frustrated by BS AI.
I avoid playing on Normal and Easy because of the experience. The experience is more intense on higher difficulties, and that's a fact that's true to games like Call of Duty and Halo, especially Halo ("Heroic : This is the way Halo is meant to be played"). AI is more aggressive and react better to your tactics.
I am playing Mass Effect 3 on hardcore, this is the first time, its not too hard. At times I even wish I started it off on Insanity because so far it's been rough but mostly smooth.
As for games like Bayonetta and DMC.. Ninja Gaiden II >_>, I have to play these games on their Normal modes because I can't handle the higher difficulties. So the genre also plays a factor. I can handle the highest difficulty on most FPS games.
Yeah but games like bayonetta and Devil may cry they kind of expect you to play a lower difficulty before moving to harder because of all the collectibles and upgrades...
I understand that, but it isnt like I jump in a higher difficulty. I beat Bayonetta twice on normal. I tried moving up but its brutal.
I play games mainly for story, so I always play on easy. I don't think I've ever played a game on hard mode.
See, I think this is the main point of contention. Traditionally, shooters (COD, SOCOM, Unreal, Quake) have very little story, so the biggest part of the fun comes from the gameplay.
I think for RPG's and the occasional action adventure game, the story is the biggest draw. Even Demon's/Dark Souls is always praised for its combat, not its setting or story. If you want a good story, then the gameplay is fluff added on for fun factor. My main driving force is to see the story unravel and connect all of the loose ends. I couldn't care less about gameplay in a game, I want to be immersed in the world.