Hi Jimmy, I don’t think there is any single best environment. It really depends on what you are using VMWare for, and what your budget is. However in my experiences I love running VMWare on HP C-Class blade systems (the c3000 chassis specifically).
I think the redundancy and power and thermal management of the blade system along with the features of VMWare are a match made in heaven. Also I would highly recommend running VMWare in a SAN based environment to take advantage of the vmotion and high availability features.
For example I have a client that didn’t want a blade system but still bought two rack mount HP DL-380 servers with dual Quad core processors and 16 GB’s of RAM each and 4 NICS in each server, and then attached them to an iscsi SAN (HP AIO in this particular case). It works great for them and they’re quite happy.