What’s the best Remote Desktop Application?
Can I remote desktop to a Windows PC from a Mac?
Yes -- an extremely good one built in called "Screen Sharing."
It is based on VNC and will work with a PC as well. Apple maintained Open Source...
For enterprise use, look at Remote Desktop.
To go to a PC from a Mac, you just need to set up VNC on the PC. If, for some reason, the Apple VNC does not work as a client to the PC side, there are many open source Mac clients as well, but the Apple VNC client / server is very robust.
The only detail to work out is if your PC is not on the local LAN. You can use VPN or SSH to screen share using VNC over the Internet as well.
Everything I described, other than Remote Desktop, is free both for the PC and Mac. It just happens to be built in on the Mac.