I hope I'm not terribly flamed for this... but here's a question:

What is a good version control system that can be served from a linux box and be used from a windows machine? GUI Client preferable but not essential if the command line interface is not like a foreign language.

RCS, CVS, and Subversion are a little too non-sensicle. Are there any other options out there? Free is *not* a requisite. The reason there must be a client for windows is the project needed version control is a .NET C# project (hence my anti-flaming preface).

A system served from a windows box would also work, but I figured I'd more likely get hits for a linux based server here :P

We tried Perforce and were not happy, and my comrade says ClearCase is horrid. Any recommendations?