I wish to present a drop down list of the System.Net.SecurityProtocolType available on the server that the code is running from (The servers are different)
So I wish to do the working equivalent of
...System.Enum.GetValues(System.Net.SecurityProtocolType)
or
...System.Enum.GetValues(TypeOf (System.Net.SecurityProtocolType))
...
(both of these complain "SecurityProtocolType is an Enum type and cannot be used as an expression")
Ideally I'd like a VB.NET solution but would be happy with C#

As others said in comments, you need to use the type:
that will give you the text values (SystemDefault, Ssl3, Tls, etc..). If you have custom display attributes you want to display, you need to use reflection, something like: