B5 is ace cakes. But......you have to watch it all, every episode, until the end of the Shadow War. Seriously. The plot is that interwoven. Can't say more. Spoilers.
DS9 is my fave Star Trek. I like the more static setting, and the way they develop the characters.
BSG is equally awesome, though goes a bit wibbly in the last season (blame the writer's strike!)
And seriously folks, do check out Space : Above and Beyond. Effects have aged somewhat, but no worse than Babylon 5. Acting and that is good. Shame it only lasted one season.
OH, and the old fall back - Dr Who. Loveitloveitloveitloveitloveit! Much nerd, very wow.