If you have two sites then you can storage vMotion to the surviving site and shutdown ESX/servers then storage and then switches. If not power-off VMs, ESX then storage and switches. This how I did two months ago for DC move (in metro environment).
Otherwise (single site)
Power off VMs
Power off ESX/Servers
Power off STorage and switches.
Power up them in reverse order (switches and storage first).