Piratecat said:
Monkeys. Poison monkeys with fangs and cool prehensile tails. I love those.
Heh - now that's entertainment. No doubt their species enemy is a race of one-eyed felinoid privateers?
I have to agree with all the posts so far: it's the sense of wonder.
I can only articulate it as that feeling I once had after first playing the game, but before ever reading the Monster Manual or the Dungeon Master's Guide.
This can be recaptured somewhat by "filing off the serial numbers", e.g., take a kobold from the MM, give it a different name and looks and maybe buff it up a little.... perhaps make it simian and hirsute, and give it an additonal poison attack...
Seriously, though, for me it's not the genre, the content or the specifics that would make an ideal fantasy setting. I suppose one could write up a laundry list of favorite components and features, or even make up a "sacred cow" list, but I'd want that sense of wonder, and of course, a top-quality piece of work for my forty bucks.