I enjoy a game that incorporates a lot of critical thinking. The sharp mind is your best ally when you've got and Quest to complete and Gp's are on the table.
I like rules... to a point. But I like creativity more. Creativity within the rules is better. I mix and match differing editions of D&D to create a world that is modeled after our physical world. People are people, physics is physics, and magic is thrown in there to make you smile. Game mechanics are designed to make the playing field even for everyone. This includes NPCs. I love a campaign who's Player Characters succeed against the odds. As a DM I will not hold the PC's hands and lead them through the dungeon. This goes for NPC's as well. The beauty of D&D is in the critical thinking/problem solving. Not in the power of the magic weapon you have written on your card.
I've been playing for 8 years, DMing and World-Building for 4.