Well, here's the thing: if it's a game that I'm supposed to enjoy for the content (story, dialog, characters, settings, etc.), then I'll play it on easy so my occasional lapses in focus won't interrupt the flow. Deep games like the original Mass Effect and other RPGs like it tend to have highly complicated combat systems, where my underestimation of the developer's willingness to be tedious tends to cost me dearly when it comes to distinguishing vital information from fluff text; easy mode allows me to treat it all as fluff. I beat Mass Effect with a rarely-upgraded assault rifle and maybe eight shots from a sniper rifle, never once using my power menu for anything other than healing (and that was only possible because of the big first aid cross), because I squarely refused to divert my focus from the parts of the game that actually interested me, and easy mode made that possible.
When the game's enjoyment is primarily derived from the gameplay mechanics, however, I usually play on the 3/4 highest difficulty setting (rounding down to medium when it's only three) because it lets me enjoy all of the gameplay content (like moves and weapons) as they were meant to be: as a necessity and an aid. A friend when you need it most, a necessary paradigm shift, instead of uninteresting offerings trying in vain to lure me away from getting complacent and clearing an Ultranationalist-occupied whitehouse with an M9 pistol and, apparently, a backpack full of 30 9mm magazines for a weapon that is meant as a last resort. Seriously, Call of Duty on easy is hard to enjoy, because it's basically a big shooting gallery where you have to run through artificially-inaccurate gunfire to pick out which gun you want to try on the unconvincingly worthless mannequins next. Normal makes me at least understand why anyone would ever want to use a shotgun that fires buckshot that magically disappears at about as far as the average person could kick off their left shoe.
