Whilst playing with Get-View today I could not work out what I needed as the ViewType for ESXi hosts. Since VirtualMachine is fairly self explanatory I figured it must be VMHost or just Host. Wrong. Either way the error was very helpful in letting me know what the valid options were. See below.

PS > Get-View -ViewType VMHost
Get-View : Cannot validate argument on parameter 'ViewType'. Accepted types: ClusterComputeResource, ComputeResource, D
atacenter, Datastore, DistributedVirtualPortgroup, DistributedVirtualSwitch, Folder, HostSystem, Network, ResourcePool,
StoragePod, VirtualApp, VirtualMachine, VmwareDistributedVirtualSwitch

Accepted types (formatted nicely):

• ClusterComputeResource
• ComputeResource
• Datacenter
• Datastore
• DistributedVirtualPortgroup
• DistributedVirtualSwitch
• Folder
• HostSystem
• Network
• ResourcePool
• StoragePod
• VirtualApp
• VirtualMachine
• VmwareDistributedVirtualSwitch