Do you care about the protocol? There are plenty of VNC clients (you'll need to install something like RealVNC on your computer but VNC works with Mac and Linux desktops as well). You can also look for RDP clients, this uses the Microsoft Terminal Services/Remote Desktop Connection protocol. There's even a Citrix client but if you don't know what that is it's too complicated to set up.
I've used Android VNC Viewer and, while functional, didn't wow me. Even still, the price is right... For my Blackberry I used RDMPlus and liked it, but they don't have an Android version (yet - feel free to pester them for one!).
I guess one more thing I should ask. Are you planning on doing this via WiFi locally or will you need to go over the Internet? If it's the latter, do you know how to deal with port forwarding on your router? If you don't know what it means when I say VNC uses port 5901, RDP uses 3389, and Citrix uses 1494 (all typical configurations) then you may want to look at something like LogMeIn. While I've never used it myself, it's apparently a pretty popular service for remotely accessing your PC.