Maltese_Falcon91
I'm guessing you recently watched the Zero Punctuation review of Dragon Age Origins?
That is entirely plausible, although I'm still not certain. Maybe I heard it more recently from someone else who watched the review. It's funny how opinions can spread like that. All I know is that I didn't come up with the idea, but I do agree with it.
Aside from that, what makes a fantasy story good is likely what makes a story of every other genre good. We've gotten a fair few threads asking "what makes X genre good?" and the answer is always the same: good writing. Interesting and engaging plot, well-developed characters, elegant and multi-sided development of issues and implications, intriguing and imaginative setting, the list goes on.
Any particular fondness I have for the genre is... well,
beyond wearing thin. I raegquit a long time ago when a certain horribly written (and, I believe, self-published) iteration of the same old Swords an' Sorcery theme had a badly-researched desert that DID NOT BEHAVE LIKE A DESERT. DESERTS (with very few exceptions) GET COLD AT NIGHT. Now I only read fantasy if it's been vetted by a lot of sources that I really trust and all of them say that it's really, really good.
That said, there is one trope that I am still rather enamored with: cursed cities. You know the ones. Ruins, mysterious circumstances, angry spirits, sins of the ancients, the works. Something about that is just hard to screw up for me. Heck, I have a story on deck (as opposed to the one on hiatus or the one, much shorter, in progress) that takes place in just such a city, only everyone isn't quite dead yet. Although I wouldn't call it straight-up fantasy. Surreal fantasy, maybe, or non-standard fantasy if I'm feeling snarky.