My favorite (using Sonya's link's names) is Mish to Furniture.
This one's got a really comprensive list (sans real models):
http://www.sexinfo101.com/sp_index.shtml
One that I used to think was ridiculous but is actually VERY cool is Crab. (or a variation of it) I was on a couch with my legs on the ground, she was on an opposing chair and we met in the middle. Each of us had leverage but our middles were kind of suspended in air. It was AWESOME, athletic with SPECTACULAR views!
P.S. Click on the Pic to see it larger and in motion (animated)