What is the best virtualization tool available? [closed]

Question

Recently my team has spent too many hours setting up machines with previous product releases or database servers with specific patches. In some cases, we have taken a developers machine down for up three days as a result. Clearly, this would be an ideal case for using a virtual machine. I am trying to champion the practice of making a virtual image of customer releases. I've used VMware effectively in the past for development and testing purposes, but I was wondering if anyone had any other virtualization tools they have had good experience using?

We are doing development in Java on Windows XP machines.

Answer 1

VMWare is the best out there IMHO.

Answer 2

I've had great experiences with VirtualBox http://www.virtualbox.org/, and I love that it's free.