I'm not really a fan of realism or bogging a game down with practicality. Despite all of the above, I also like a game to acknowledge that it is a game. This means that gameplay mechanics don't need to be hidden, character and world designs can exist in such a way that doesn't require an explanation (i.e. I prefer things like ornate costumes whose only function is to make characters stand out from the crowd, skinny-armed teenagers can dual wield swords twice their size, etc.) and the laws which govern a game's world don't necessarily need to be infallible (the game can bend the rules to accommodate story, for instance).
Going along with the above, blow my mind when it comes to characters, worlds, abilities, etc. Using the Final Fantasy series as an example (yeah, again), I've visited futuristic (occasionally dystopian-esque) cities, a floating continent, a crystallized lake, a castle made up of memories, been into space.. twice, have seen a villain actually destroy the world, etc. Compared to that, realistic medieval fantasy doesn't quite cut it. These are video games, where the worlds you create are limited only by your imagination. Better yet, we actually have the ability to explore these worlds. Get creative.
Other than that, it's hard to say. Obviously my post was geared toward RPGs, and there isn't really one style of gameplay that I'd say is perfect for me. Just as long as it isn't first-person.