What's the closest C # "Python interpreter" equivalent?

This is what I mean:

The Python interpreter is a great tool for inspecting something quickly and then throwing it away.

For example, I would like to study how it NameValueCollection

behaves in .Net (since the new MSDN support is so high).

http://msdn.microsoft.com/en-us/library/system.collections.specialized.namevaluecollection.get.aspx

I tried using http://www.linqpad.net/ but it barks when using operators.

I'm looking for something like this - a tiny IDE that has powerful code completion where I can quickly try. VS2008 is too cumbersome for this.

So, any recommendations? Thanks!