If you are running VMWare server/workstation, you will find the following Vmware parameters useful.
mainMem.useNamedFile = "False"
This parameter is helpful if you have a slower disk like flash drive or drivers like ntfs-3g.
tools.syncTime = "TRUE"
Syncs the VM's clock with the host. Helpful to avoid time slips while running VMs.
MemTrimRate = "0"
Vmware, by default, trims the unused VMs memory and gives it back to host OS. This parameter disable the behavior. While this results in increased memory usage per VM, it also improves the VM performance.
Sched.mem.pshare.enable = "False"
Disables page sharing across VMs. This is again useful on systems with large amount of memory.
prefvmx.minVmMemPct = "100"
If you have a huge amount of memory, you might want to "pre-allocate" all allocated memory. It gives good performance boost but obviously limits the number of VMs you can run on the host.
Hope you find these parameters useful.