Babylon 5 aired from 1994 to 1998. The creation of J. Michael Straczynski, it was groundbreaking in its time and I think it stands up very well today. The show featured the most advanced and extensive CGI effects to date, and set a whole new standard for CGI production. It also marked a departure from the procedural format common in TV series - in which each episode is a self-contained story, and the episodes may be watched interchangeably in any order - toward a serial format, in which an extended story arc is developed from one episode to the next over the length of a season or even the series. The premise of B5 is a space station located in deep space, and hosting visitors and diplomats from various spacefaring races. A similar concept was used in 'Star Trek: Deep Space Nine' and Straczynski maintains that the Star Trek franchise stole his idea, although he declined to pursue legal action. B5 was notable for its dramatic sophistication and strong character development.
Battlestar Galactica, which aired a decade later, was Ronald D. Moore's 're-imagined' production of a 1978 TV series of the same title. In the pilot mini-series, the human race (an Earth-like, spacefaring civilization spanning twelve planetary 'Colonies') is wiped out following a war with robots of its own creation, called Cylons. Only about 50,000 humans survive aboard the spaceship of the series title. This show too set a new standard for CGI effects and for dramatic production. The scenes have a gritty, lifelike feel which Moore said was part of a conscious effort to differentiate the series from the 'Star Trek' model. Much of the tension comes from internal conflicts among the protagonists, sometimes overshadowing the external threat from the Cylons.
So I've started watching both shows from the beginning, more or less alternating by episodes. Vorlons to the left of me, Cylons to the right! This is gonna be fun.