I am in pain thinking about anyone watching
In the Beginning first.
WAY too spoilery
Plus, as a introduction to the world it suffers from the fact that one of the major characters from the first season, who plays an essential role in ending the war the Movie is about, wasn't avaliable when they filmed the film and only appears in stock footage.
Meaning that, for anyone watching it cold, it must seem really odd to have this guy who hasn't been in it before show up five minutes from the end and shut the whole plot down.
EDIT: Legend of the Rangers was piss poor.
I was actually surprised on my recent rewatch how much I enjoyed Crusade (which I'd seen a couple of at the time but had found a bit crap). It's by no means perfect, and you can definately see the impact of the behind the scenes problems, but it's saved by some excellent casting (the fact Gary Cole isn't a bigger TV star is a crying shame) meaning it's never less than watchable.
Legend of the Rangers on the other hand, which again I only watched properly for the first time this time through, had all the bad points of Crusade and none of the good ones. Other than the carry over of G'Kar the cast are the blandest, dullest group of characters in the entire history of television. Especially compared to B5, which certainly had a few cast members take a while to find their feet but still had some real stand out performances right from the off.