Because I've spent a lot of time on story-games recently, let's throw some love to the Big Purple. An interesting thread came up entitled The older I get, the less I want fantasy (in which the poster feels that his liking for the fantasy genre has declined with age, and he now prefers historical or modern-era gaming).
This struck a bit of a chord with me, though my feelings aren't quite the same as him. For me, what I can definitely say is that fantasy fiction has lost its lustre as I've got older. From the age of 11 or so, when I first read The Lord of the Rings, to the age of about 25, I read absolute shit-tons of fantasy novels. (And most of it was shit.) You name the series, I'd probably read at least one volume and probably the lot.
Nowadays, I barely read any, and to be frank, while the Fantasy & SF section is the first one I go to when I go to a bookshop, whenever I pick up a new fantasy book and flick through to see what it's like, it usually makes me cringe. Boring, samey writing; banal dialogue; by-the-numbers plots; awful unimaginative world-building dressed up as "unique" settings; inside-front-cover maps covered with place names like 'Franconia' and 'L'k'xhklhaj'... It's a veritable hell-on-earth of literary bollocks, only a step removed from Mills & Boon, and without the compensating factor of sex (unless it's GRRM, who only writes The Most Stupid Sex Scenes EverTM anyway).
There are nowadays only a handful of fantasy authors who I can really stand to read: Tolkien, Dunsany, Howard, M. John Harrison, China Mieville, Wolfe, Vance, and, okay, GRRM, because I have to finish off that bloody series if it kills me. The rest of the genre can go hang, quite frankly.
But this is why, I think, I'm still very much into fantasy gaming: a function of finding modern fantasy literature so soul-destroyingly awful that I can't bear to read it is that I have to get my imaginative kicks elsewhere.
Moreover, I'd say that if what you're interested in is expanding your mind, imagining weird shit, dreaming up half-crazed nonsense, escaping somewhat humdrum reality, and many of the other things that fantasy lit is supposed to do, I'd argue that fantasy gaming does it much better. Your imagination is constrained far less if you and your friends are the ones coming up with the entire thing - if you are not letting some third-rate author do your imagining for you - so why have cotton when you can have silk?
In fact, maybe that's what my rule of thumb for fantasy literature is: from now on I'll look at the blurb on the back of the book, and if the whole thing sounds like I could imagine something better in a session of D&D, the author isn't trying hard enough and the book gets binned. If I can't imagine something better in a session of D&D, it's worth a try.