$myCol = @()
ForEach ($VMHost in (Get-VMHost | Sort Name))
    {
    ForEach ($VM in ($VMHost | Get-VM))
        {
        ForEach ($NIC in (Get-NetworkAdapter -VM $VM))
            {
            $myObj = "" | Select VMHost, VM, NIC, PortGroup, vSwitch
            $myObj.VMHost = $VMHost.Name
            $myObj.VM = $VM.Name
            $myObj.NIC = $NIC.Name
            $myObj.PortGroup = Get-VirtualPortGroup -VM $VM -Name $NIC.NetworkName
            $myObj.vSwitch = $myObj.PortGroup.VirtualSwitchName
            $myCol += $myObj
            }
        }
    }
$myCol | Group-Object VMHost, vSwitch -NoElement | Sort Name | Select Name, Count