v1 The Fightin' Scientists of Tesladyne - 6 issues
v2 Dogs of War - 4 issues
v3 Shadow From Beyond Time - 5 issues
v4 The Revenge Of The Vampire Dimension - 4 issues
v5 Deadly Art of Science - 5 issues
v6 The Ghost of Station X - 5 issues
v7 Flying She Devils of the Pacific - coming soon
The trades are super nice because they are each one volume (plus extra stuff). You can pick out whatever trade you want and not worry about the others, since they are all self-contained. My favorite is Shadow From Beyond Time.