Galactica was misunderstood. Many people tended to see it as a rogue series that was attempting to leech off of Star Wars' success. Indeed, much of the special effects and plot elements could be compared to examples seen within Star Wars', but the series definately had an identity of its own.
The cast is strongly anchored by the fatherly Lorne Green, who previously played Ben Cartwright on Bonanza (amongst other projects). In addition, John Colicos plays the evil Baltar, and does a good job at getting the viewer to hate his character.
The charm of the original Galactica is its overall simplicity. We don't see the complication and challenges that are shown in the modern Battlestar Galactica (2003). There are no cylons that look like humans, no crazy scientists with cylon women stuck in their head, no real secretive hidden agendas and coups, nothing. The characters were very stoic, the viewer knew how they felt and why they did what they did. The crew onboard the original Galactica is far more stable and functional than the crew on the new Galactica. Some might argue that the dynaism of the new crew makes the series more intriguing, but I still love the classic series with its charming characters and story lines.