Adventure:
Deep storyline with plenty of interaction between characters.
Fighting: both with brains and skill, so not just hitting them with a weapon, but having to think and react fast.
Dungeons: The more the better, with progressively harder enemies and layouts.
World: open world, able to go where you want provided you have certain abilities or items to give you access.
Bosses: The toughest thing you've faced yet, but once you've beaten them it's fun to go back and do it again.
Items: A whole range, designed to suit any task, but collected as you progress in the game.
Collectibles: Loads and Loads of collectibles scattered all around the world.
Sidequests: Both short one-quest breaks and longer mini-plot breaks from the main storyline/
Enemies: Both easy and hard, usuall with some kind of critical weakness to each one (shoot it's eyes, throw water at it, e.t.c)
Money: Being able to get it from almost anywhere and have worthwhile stuff to spend it on.
Health:Having just enough that you're always thinking you're about to die, but never quite reaching it. Also upgradeable.
Magic: Usually superhuman stuff, like instant healing potions, spells and ancient technology (whether it's called magic or not)
Other stuff: tends to have mystical ancient legends popping up everywhere.
Thats my thoughts. If you think I've missed anything just tell me
