OpenGL feasibility?

Hi all.

A couple of years ago I programmed (Read:messed around with) predominantly in OpenGL. I really enjoyed the syntax as it was simple and had much support from the Open community.
Now that I've abandoned C++ and switched to C# because of its ease with the .NET framework and workspace requirements, I lose the native OpenGL functionality.
I know there are several libs available for OpenGL support but is it still worth it? I haven't really touched OpenGL 2.0 but is it as "advanced" as D3D is nowadays?

Thanks for the replies in advance.