Tactics-Very Important. Charging into battle without thought and strategy gets you killed.
Story-I do my best to tell an interesting story (which the PCs usually change)
Player vs Player-One of my players is plotting to take out another player right now.
Mirror- A week ago someone said, "It'd be awesome to fight a full-on dragon". This week the PCs fought a Blue Dragon.
GM is In Charge- Uh-huh.
Improvisation-I have a map and stats for NPCs. Everything else is improv.
"Beer-and-Pretzels"- We don't have serious games. I have spent half a game session watching players knocking on villager's doors and harassing them.
Tinkering-You know what? Sometimes, there's too many rules. Sometimes, I want to swing a sword without checking for encumbrandce, speed of swing, sword strength, chance of breakage, etc., etc.