Is there a Remote Desktop Connection manager for mac that will connect to Windows machines? I am managing 4 Windows VM's on a network for running tests. I would like a Remote Desktop Connection manager that makes it easy to connect and switch between network machines. 

I am due for a hardware upgrade, and would like to switch to a Mac for a variety of reasons, but being able to manage my RDP sessions easily is a must.

Free software is a plus.
Microsoft Remote Desktop from the Mac App Store may work for you. Lots of VNC client/servers out there too. RealVNC for example. You can use Apple's built-in Screen Sharing app to connect to 3rd party VNC servers running on your Windows PC. Just do a Command-K to connect to server and enter vnc://address.