Hi,
As everyone know that Command Line is best tool for doing thing fast.
To Shutdown a VM or a Group of VM you can use the following Command
Shutdown-VMGuest [[-VM] <VirtualMachine[]>] [[-Server] <VIServer[]>] [-WhatIf] [-Confirm] [<CommonParameters>]
Shutdown-VMGuest [[-Guest] <VMGuest[]>] [-WhatIf] [-Confirm] [<CommonParameters>]
Example 1
Get-VM VM | Shutdown-VMGuest
for more Information vSphere 5.5 Documentation Center