I have been known to say that "the more realistic a game is, the less likely I am to enjoy it." It's not always true, though, so I decided to give it some thought and really figure out where that correlation comes from. It's not like I make up catchphrases just to have something to say. Like stereotypes, even though each case has to be treated individually and granted respect or ridicule based on its own merits, it does have some real basis.
It's not the realism in games that turns me off. Realism is, at its core, completely unrelated to the game itself. A game is a game regardless of what it looks like, and its merits and detriments are mostly based off the gameplay. The graphics can affect gameplay, sure. You want to be able to tell what's going on. I'm not saying that all first person shooters could be rendered in wireframe mode and still be just as compelling.
Crysis isn't a good game because it looks pretty. Half-Life isn't a bad game because its graphics are outdated. These things are completely separate from what makes a game enjoyable. Half-Life's hallways and overall construction is mostly devoid of detail. It was a hardware limitation at the time--too many polygons and the computers wouldn't be able to run it. But the level layouts were still compelling, the enemies were interesting, the story was great, and most importantly, the gameplay was superb.
Half-Life wasn't just "a good game for its time", it's "a good game", period. It still is, and it always will be.
That being said, the reason that realism correlates to less enjoyable games, I think, is because the developers spend way too long trying to make the game realistic, and not long enough making the game fun. They have the wrong focus.
We play games to do stuff we couldn't do in life. Games must sacrifice some elements of realism to make the gameplay more interesting, or else why even bother calling them games? A game that religiously adheres only to things that could happen in the real world is more of a chore than a game, and has nothing interesting going for it that would draw me in to play in the first place.
Call me old-school, but given the choice, I'll take my core gameplay over pretty moving pictures any day.