I recently switched to a real PC. I bought a cheap Dell computer for maybe a couple hundred dollars more than the Parallels software. I stuck the computer behind my desk, plugged it into the network and then I leave it on. I then use the Apple Remote Desktop Connection Client to connect to the Dell.
This is so much faster then running Parallels. I can connect at work or at home, via the VPN. I can print, copy and paste between Mac and PC and always email documents back and forth. Just as my Mac (which is still less than two years old) gets older, Parallels slows down and it takes forever to do the tasks I need it to do.