I am an avid Babylon 5, and whilst I agree the first season is not that much cop, there are some *KEY* episodes that fit in to season 2, and Three.
Episodes like 'Voice in the Wilderness' (Parts 1 and two), this is where they introduce Draal and the 'Great Machine' on the planet below, Bester is introduced (Walter koenig), as well as a *VERY IMPORTANT* episode regarding what happened to Babylon 4 as well as a *KEY* story to quite important episodes of later seasons.
Even myself who has seen the series a number of times, still get a WTF feeling from how some of the stories can really turn your head inside out trying to keep up.
Babylon 1, 2 and 3 were destroyed by sabotage, Babylon 4 "Vanished" without a trace, and B5 is to be the LAST. Season 1 episode "Babylon Squared" gives a view as to what happened on board B4 when it disappeared, and then followed on in Season 3. It still trips me out how the hell JMS (the writer/producer) pulled it off.
Season 1 also lays the foundation for the hostility between J'Kar and Londo and the events that unfold from that in later season (like the Narn/Centuri war).