My own viewing order, compiled from a multitude of sources and my own opinions on continuity issues as I watch the series.
Sources:
- http://www.midwinter.com/lurk/countries/master/eplist.html
- http://scifi.stackexchange.com/a/10015/31492
- http://scifi.stackexchange.com/a/21381/31492
- http://www.b5tv.com/showthread.php?t=11675
- http://johan.kiviniemi.name/blag/b5/
- The Gathering
1x01Midnight on the Firing Line1x02Soul Hunter1x03Born to the Purple1x04Infection1x05The Parliament of Dreams1x06Mind War1x07The War Prayer1x08And The Sky Full Of Stars1x09Deathwalker1x10Believers1x11Survivors1x12By Any Means Necessary1x13Signs and Portents1x14TKO1x15Grail1x16Eyes1x18A Voice in the Wilderness part 11x19A Voice in the Wilderness part 21x20Babylon Squared1x21The Quality of Mercy1x17Legacies1x22Chrysalis
2x01Points of Departure2x02Revelations2x03The Geometry of Shadows2x04A Distant Star2x05The Long Dark2x06A Spider in the Web2x08A Race Through Dark Places2x07Soul Mates2x09The Coming of Shadows2x10GROPOS2x11All Alone in the Night2x12Acts of Sacrifice2x13Hunter, Prey2x14There All the Honor Lies2x15And Now For a Word2x17Knives2x16In the Shadow of Z'ha'dum2x18Confessions and Lamentations2x19Divided Loyalties2x20The Long, Twilight Struggle2x21Comes the Inquisitor2x22The Fall of Night
3x01Matters of Honor3x02Convictions3x03A Day in the Strife3x04Passing Through Gethsemane3x05Voices of Authority3x06Dust to Dust3x07Exogenesis3x08Messages from Earth3x09Point of No Return3x10Severed Dreams3x11Ceremonies of Light and Dark3x13A Late Delivery From Avalon3x12Sic Transit Vir3x14Ship of Tears3x15Interludes and Examinations3x18Walkabout3x16War Without End, Part One3x17War Without End, Part Two3x19Grey 17 Is Missing3x20And the Rock Cried Out, No Hiding Place3x21Shadow Dancing3x22Z'ha'dum
4x01The Hour of the Wolf4x02Whatever Happened to Mr. Garibaldi?4x03The Summoning4x04Falling Toward Apotheosis4x05The Long Night4x06Into the Fire4x07Epiphanies- (First 2 minutes only, stop after scene with Zach)
4x09Atonement - Thirdspace
4x08The Illusion of Truth4x09Atonement- In The Beginning
4x10Racing Mars4x11Lines of Communication4x12Conflicts of Interest4x13Rumors, Bargains and Lies4x14Moments of Transition4x15No Surrender, No Retreat4x16The Exercise of Vital Powers4x17The Face of the Enemy4x18Intersections in Real Time4x19Between the Darkness and the Light4x20Endgame4x21Rising Star4x22The Deconstruction of Falling Stars
You can pretty much consider this entire season as one long epilogue. It's enjoyable, but the main storyline wraps up after season 4, so don't set your expectations too high for this season.
5x01No Compromises5x02The Very Long Night of Londo Mollari5x03The Paragon of Animals5x04A View from the Gallery5x05Learning Curve5x06Strange Relations5x07Secrets of the Soul5x09In the Kingdom of the Blind5x10A Tragedy of Telepaths5x11Phoenix Rising5x12The Ragged Edge5x08Day of the Dead5x13The Corps is Mother, The Corps is Father5x14Meditations on the Abyss5x15Darkness Ascending5x16And All My Dreams, Torn Asunder5x17Movements of Fire and Shadow5x18The Fall of Centauri Prime5x19Wheel of Fire5x20Objects in Motion5x21Objects at Rest- [1 year later] River of Souls
- [2 years later] (not really worth it IMO, and has chronology issues) The Legend of the Rangers
- [5 years later] A Call To Arms
- [10 years later] (skip the first episode, it's ridiculous) The Lost Tales / Voices in the Dark
- [20 years later]
5x22Sleeping in Light
I didn't watch any of these, but if you want to, they go after A Call To Arms at the end of Season 5
Crusade e01-e13 (see: Lurker's Guide for order)
FYI, the most popular Babylon 5 Viewing Orders for all TV Episodes and Movies are now listed here: https://babylon5.fandom.com/wiki/Viewing_Order