The Elephant Tour
I usually don't take group tours because of the limited flexibility, but here in Chiang Mai I had a great experience. I took the 'Elephant' tour from one of the numerous tour operators in town. We rode Elephants through the hills, visited remote Tribal Villages and went down the river on a bamboo raft. (Yes, the Elephants stayed behind....)
These are mostly things that I couldn't have arranged myself anyway.I met great people from four different continents, and had a wonderful day.