Out of curiosity what games (or perhaps what are the most recent games) have you played on easy and why? I say it doesn't count if a game has only 1 difficulty available at first, or if the default is the lowest option, you need to have manually picked a lower than default difficulty on a game for some reason.
I used to play games on easy all the time (games like Goldeneye and Perfect Dark) because I sucked at games as a kid. But I moved past that pretty quick during the PS2 XBox GC era, however recently I have chosen to plow through some games on lower difficulty settings just to plow through them faster, mostly for brief rentals.
Uncharted the first was quite fun on easy, It was a rental. I wanted to see the story before playing 2 but had heard the combat dragged a bit because of bullet spongy enemies. Not a problem on easy.
Black Ops was another rental, I was curious about the story but without spec ops there is not enough to justify a purchase for me, as I'm not big on the multiplayer. It was ok, but even on easy I found myself dying surprisingly frequently as I guess I was reckless.
COD4 to get all the intel on easy for the S-rank, because that was all I was missing after I got Mile High Club. That was fun running through places that I remembered being such a bitch the first time on Veteran 4 years ago and Ramboing my way through them. (A lot of me thinking things like "Oh hey I remember you, I'm going to knife you in the stomach. Asshole. You deserve it.")
As an aside I've found that with game difficulty I have a preference for a game to be either hard enough to provoke a feeling of accomplishment (COD4 on Veteran was great for that) or easy enough that there is no frustration at all while playing (I like the Prince of Persia 08 game a lot for that reason) but most games nowadays seem to be designed in some murky middle ground that just is not as fun for me.