Macworld published a review of much acclaimed Parallels Desktop for Mac, including an interesting benchmark comparison and providing this conclusion:
Parallels’ ability to run nearly every version of Windows, along with many versions of Unix and Linux, makes it a valuable tool for anyone using an Intel-based Mac who has a need or desire to work with other operating systems.
If your job requires Windows, but you love your Mac and OS X, Parallels will truly give you the best of both worlds. If you put your Parallels session in full screen mode, anyone walking by won’t even be able to tell that under the Windows façade, you’re actually running the world’s greatest operating system.
Read the whole review at source.