Virtualization has become fairly common now and can be easily used by average IT professionals. I've used most hypervisor platforms and have settled on using Microsoft's Hyper-V software. With the latest version of “2012 R2” and “8.1”, Microsoft's offering has finally mature enough for me to adopt it full time. I use it both on the desktop for short-term testing and longer-term production use. Using PowerShell to deploy and manage virtual machines is a great method of management.
I also used the following hyper-visors in the past: