The only thing I would say we don't do is really heavy roleplaying. Sessions usually run as a mix between problem solving, combat, and interaction with NPC's. We usually manage to have two or three NPC's per campaign that really catch the attention of the players and stick around as contacts and such. We also have a real tendency to end up working complex math problems (like the pressure involved in a decanter of endless water and how much force the flow would produce, would it be capable of propelling a ship?). We decided yes but not very well.
In eighteen months we have had a campaign in my tolkienesque Medara setting, a summer break Mutants and Masterminds conspiracy kind of thing, a short first DM outing in a fantasy United States, and our current 6 month campaign is set in a new world we are putting together from published stuff. So far, it includes Shak-la (a big city I made up that includes the Cauldron from the Dungeon Adventure Path), the Mindscapes setting from Green Ronin, and parts of Al-Qadim.
We have plans for Dark Sun next from one of the players, then back to me for Ravenloft, then probably me for a Norse flavored campaign.