1. Stargate SG-1
Fun, child friendly most of the time, more intelligent than a lot of military shows or scifishows.
2. Stargate Atlantis
Same reasons as the first, but also the better bad guys and the amount of humour that was added to the show. Not to mention I just love Zelenka and Todd.
3. Babylon 5
Very intelligent, very humorous but in an intellectual way, very witty, very political.
Amazing creature design, best aliens out there. Storyline less good, but the monsters really make it.
More sciency and less fictiony, but still amazing and amazingly funny. And so child friendly that I almost cry of joy when I don't have to see murder and sex all the bleeding time.