'Babylon 5' always felt infinitely more realistic to me. It dealt with down and dirty subjects, like how poverty and political back-stabbing would still prevail just as much as it tends to today, even in the distant future. Also got lots of acclaim from people at NASA for trying to make the ship designs scientifically possible (even down to the correct rotation to give the station gravity).
Rodenberry had some very strange ideas about his own creation, later on in life...