It is into the best part of the story, or just when the thing starts to go up real quick, and it presents all the station to a ficticional newbie (aka. "the people who watches ISN") so I find it perfect to show it to a "real" newbie.
I have tried to introduce several of my friends to the show. I have not had much success so far. I do believe that a course of action is best decided by the willingness of the person to bare with some tedious episodes. If they are very willing to wait for the pay off then The Gathering is the best one to show them. Then, show them important episodes from the first season. My dad got me into the show during the second season, and I ended up being a bigger fan than him. I later went back and watched first season episodes and the important ones had much more meaning.
If a person is less willing then I suggest starting with ItB and then pick up with the last few episodes of season 1. Explain backstory to help them understand. I found the best books in terms of getting the most out of the episodes. Pick up, The Babylon File by Andy Lane. It lays out the plot lines, story arc, observations, dialogue to rewind for, and my personal favorites, koshisms and ivonava's life lessons. It will help the seasoned fan pick up things that they missed and help newbies to understand the Babylon 5 universe.
I am about to start on a new friens. We will see how my new plan works.
No one here is exactly what he appears.