Actress Richardson died in March 2009, at the age of 45, from head injuries following a skiing accident in Canada.
Neeson, 61, spoke out about his loss in an interview with US show 60 Minutes conducted at his New York State farmhouse, where the couple were married in 1994.
The Non-Stop star recalled working with Richardson when they starred together in Anna Christie on Broadway in 1993.
"She was a radiant beauty. This cascading hair I remember, that was very, very attractive," he said. "I'd never had that kind of an explosive chemistry situation with an actor, or actress. She and I were like (Fred) Astaire and (Ginger) Rogers. We had just this wonderful kind of dance, free dance on stage every night, you know?"
Neeson was filming a movie in Toronto when Richardson suffered a fatal brain haemorrhage on a skiing holiday in Quebec, when she fell on a beginner's slope and hit her head. She was not wearing a helmet and reportedly refused medical treatment on the scene, but returned to her hotel where she was taken ill.
The Star Wars actor recalled: "I spoke to her and she said, 'Oh darling. I've taken a tumble in the snow.' That's how she described it."
He went on: "I flew up immediately. When I was in the air the pilot was told, 'Listen, divert your flight to Montreal because she's gonna be taken to the - the big hospital in Montreal.' I got a taxi to this hospital and uh - this doctor, he looked all of 17, showed me her X-ray. And you didn't need to be a rocket scientist to see what was happening.
"It was like a cartoon. The brain's squashed up against the side of the skull - as the blood tries to get a release."
He continued: "I was told she was brain dead. And seeing this X-ray it was, like, 'Wow.' But obviously she was on life support and stuff. And I went in to her and told her I loved her. Said, 'Sweetie, you're not coming back from this. You've banged your head. It's - I don't know if you can hear me, but that's - this is what's gone down. And we're bringing ya back to New York. All your family and friends will come.' And that was more or less it."
"She and I had made a pact - if any of us got into a vegetative state that we'd pull the plug. So when I saw her and saw all these tubes, that was my immediate thought, these tubes have to go.
"But donated three of her organs, so she's keeping three people alive at the moment. Her heart, her kidneys and her liver... I think she would be very thrilled and pleased by that too, actually."
The actor admitted he still struggles to come to terms with her loss five years on.
"It was never real. It still kind of isn't," he confessed.
"There's periods now in our New York residence when I hear the door opening - she would always drop the keys on the table and say hello. So any time I hear that door opening I still think I'm going to hear her.
"Grief hits you like a wave, you get this profound feeling of instability. You feel like a three legged table. The earth isn't stable any more.
"It passes, becomes more infrequent, but I still get it sometimes."
Neeson has to adjust to being a single parent to sons Michael, 19, and Daniel, 18, which he said, "could have been a hell of a lot worse".
The Taken star returned to work just days after Richardson's funeral and has made 20 films since her death.
"I'm not good without work," he said. "I just don't - I just don't wallow too much. You know? And I just didn't want to - especially for my boys - seem to be wallowing in sadness or depression."