Babylon 5 creator and writer J. Michael Straczynski wrote such engaging, heart felt and often poetic dialogue, that it is impossible to narrow down a collection of quotes from the series that completely does it justice. Though I am sure there are many missing, the collection of quotes here are what I have picked out as the most significant. Quotes can be found within the individual episode guide pages but have also been linked directly below:

Season 1: Signs and Portents

Midnight on the Firing Line | Soul Hunter | Born to the Purple | Infection
The Parliament of Dreams | Mind War | The War Prayer | And the Sky Full of Stars | Deathwalker
Believers | Survivors | By Any Means Necessary | Signs and Portents | TKO | Grail | Eyes
Legacies | A Voice in the Wilderness (1) | A Voice in the Wilderness (2) | Babylon Squared
The Quality of Mercy | Chrysalis

Sinclair: It was the dawn of the third age of mankind. Ten years after the Earth Minbari war. The Babylon project was dream giving form. It’s goal to prevent another war by creating a place where humans and aliens could work out their differences peacefully. It’s a port of call. Home away from home for diplomas, hustlers, entrepreneurs, and wanders. Humans and aliens wrap in two million five hundred thousand tons of spinning metal, all alone in the night. It can be a dangerous place, but it’s our last best hope for peace. This is the story of last of the Babylon stations. The year is 2258. The name of the place is Babylon 5.

Season 2: The Coming of Shadows

Points of Departure | Revelations | The Geometry of Shadows | A Distant Star | The Long Dark
Spider in the Web | Soul Mates | A Race Through Dark Places | The Coming of Shadows | GROPOS
All Alone in the Night | Acts of Sacrifice | Hunter, Prey | There All the Honor Lies
And Now for a Word | In the Shadow of Z’ha’dum | Knives | Confessions and Lamentations
Divided Loyalties | The Long, Twilight Struggle | Comes the Inquisitor | The Fall of Night
Sheridan: The Babylon Project was our last, best hope for peace. A self-contained world five miles long, located in neutral territory. A place of commerce and diplomacy for a quarter of a million humans and aliens. A shining beacon in space, all alone in the night. It was the dawn of the Third Age of Mankind… the year the Great War came upon us all. This is the story of the last of the Babylon stations. The year is 2259. The name of the place is Babylon 5.

Season 3: Point of No Return

Matters of Honor | Convictions | A Day in the Strife | Passing Through Gethsemane | Voices of Authority
Dust to Dust | Exogenesis | Messages from Earth | Point of No Return | Severed Dreams
Ceremonies of Light and Dark | Sic Transit Vir | A Late Delivery from Avalon | Ship of Tears
Interludes and Examinations | War Without End Part 1 | War Without End Part 2 | Walkabout
Grey 17 Is Missing | And the Rock Cried Out, No Hiding Place | Shadow Dancing | Z’ha’dum
Ivanova: The Babylon project was our last best hope for peace. It failed. But in the year of the shadow war, it became something greater, our last best hope for victory. The year is 2260, the place Babylon 5

Season 4: No Surrender, No Retreat

The Hour of the Wolf | Whatever Happened to Mr. Garibaldi? | The Summoning
Falling Towards Apotheosis | The Long Night | Into the Fire | Epiphanies | The Illusion of Truth
Atonement | Racing Mars | Lines of Communication | Conflicts of Interest | Rumors, Bargains and Lies
Moments of Transition | No Surrender, No Retreat | The Exercise of Vital Powers
The Face of the Enemy | Intersections in Real Time | Between the Darkness and the Light
Endgame | Rising Star | The Deconstruction of Falling Stars
Lennier: It was the year of fire.
Zack: The year of destruction.
G’kar: The year we took back what was ours.
Lyta: It was the year of rebirth.
Vir: The year of great sadness.
Marcus: The year of pain.
Delenn: and the year of joy.
Londo: It was a new age.
Franklin: It was the end of history.
Ivanova: It was the year everything changed.
Garibaldi: The year is 2261. The place:
Sheridan: Babylon 5.

Season 5: The Wheel of Fire

No Compromises | The Very Long Night of Londo Mollari | The Paragon of Animals
A View from the Gallery | Learning Curve | Strange Relations | Secrets of the Soul | Day of the Dead
In the Kingdom of the Blind | A Tragedy of Telepaths | Phoenix Rising | The Ragged Edge
The Corps is Mother, the Corps is Father | Meditations on the Abyss | Darkness Ascending
And All My Dreams, Torn Asunder | Movements of Fire and Shadow | The Fall of Centauri Prime
The Wheel of Fire | Objects in Motion | Objects at Rest | Sleeping in Light
Kosh: And so it begins.
Minbari assassin: There is a hole in your mind.
Sinclair: What do you want?
G’kar: No one here is exactly what he appears.
Sinclair: Nothings the same anymore.
General Hague: Commander Sinclair is being reassigned.
Londo: Why don’t you eliminate the entire Narn homeworld while you are at it.
Elric: I see a great hand reaching out of the stars.
Sebastian: Who are you?
ISN Reporter: President Clark has signed a decree today, declaring martial law.
Sheridan: These orders have forced us to declare independence.
Bester: Weapons supplies.
Sheridan: Unless your people get of their encounter suited butts and do something.
Zathras: Your the one who was.
Kosh: If you go to Z’ha’dum you will die.
Lorien: Why are you here?
Lorien: Do you have anything worth living for?
Delenn: I think of my beautiful city in flames.
Sheridan: Giants in the play ground.
Sheridan: Now get the hell out of our galaxy.
Sheridan: We are here to place President Clark under arrest.