which .net Physics Engine to use

Hi guys, im currently working on a game in ODN that requires some physics. I therefor need a physics engine to use with ODN. I've been looking around for them, but they seem to be quite sparse, so my question is: which one do you use?

For our project @school we chose to use ODE, based on the tao framework. After a couple of days fighting with the engine we managed to create a basic collision detection system.

We're now at the stage of tweaking things