Salut! Live

For good, rough-hewn honesty, I'd choose your bonus version - Behan singing his brother's song. Otherwise, of those offered here, the Pogues for keeping it down and dirty.
I'm generally a fan of Glen Hansard but not for this. (Incidentally, his "Falling Slowly" isn't from "The Commitments," which was all Motown, but the fabulous 2007 movie "Once," starring Hansard and Markéta Irglová.) With all those people on stage, worthy as they are, the song is buried beneath a mish-mash of styles and, I fear, egos.
I was never much enamoured of The Dubliners and Luke Kelly's rendition leaves me cold - it's too mannered and I really hope that echo on his voice is natural and not induced.
Bob Dylan's version is on The Basement Tapes album but doesn't seem to be anywhere on-line, not even Spotify. I believe it also features The Band - I really must hunt it down.
As you say, there are lots of interpretations of The Auld Triangle, including a glorious punked-up assault on the song by the Dropkick Murphys. Not for those of delicate sensibilities. The version from the fairly dire (apart from the music) Coen Brothers' 2013 folk-scene-in-1961-New-York film "Inside Llewellyn Davis" is commendable, though some of the performers may seem incongruous: Justin Timberlake, Chris Thile, Chris Eldridge, Marcus Mumford, & Gabe Witcher. Still, here it is:
https://www.youtube.com/watch?v=zCVIEh0n1o4

A powerful song – stirring, compelling, and a bit haunting too – it gives me goosebumps if it's sung by the right voice and in the right atmosphere.
I'm afraid the version with Glen Hansard and friends doesn't fall into that category at all. Sorry – and with all due respect to all those big names on stage – but this rendition does absolutely nothing for me. Comes over like a nice happy sing-along at a jolly family gathering.
I wasn't aware of the fact that Bob Dylan has sung this song either. To be honest, I can't imagine he has – or ever had – the voice for it. I found a listening sample on Amazon and that more or less confirmed my suspicions. Would be interesting to hear the whole thing, but the bit I heard definitely didn't bowl me over.
I've heard this song live dozens of times. For a long time it was the final song of the first set at almost every Dubliners' gig. Patsy Watchorn's a cappella rendition will always be one of my favourites, very often you could hear a pin drop in the audience when he performed this. (Unless of course the concert happened to be in Dublin, where everyone feels the need to sing along!) And when the rest of the band harmonised the chorus you could almost hear the jingle-jangle along the Royal Canal banks.
But credit where credit is due, I've experienced other excellent versions. The song is part of the Kilkennys' repertoire, for instance – Davey Cashin & Co. make a very impressive job of this.
Having said all that – in the end I think Luke Kelly's rendition takes some beating. His voice simply had the power and the passion that this song needs. And of course this was a special song for Luke - it was the song that started off his love of folk music, the night he visited his first ever folk club way back in the early 1960s - The Folk Song and Ballad in Newcastle (moved a couple of years later to the Bridge Hotel and changed its name accordingly).

Anyway - the Royal Albert Hall performance is one of the very few instances when John Sheahan sang solo in public. He did sing The Travelling People once, but it was backstage and it was with me ;-) (sorry, couldn't resist)

For your passing interest, the film version of The Quare Fellow is on YouTube in decently high definition. It's most certainly worth a look
https://www.youtube.com/watch?v=uWjehoS1aRs

I've sung this myself a capella in front of a pub full of Irish people, and it went down so well i was asked to do it again the next night. I love the song.

The song was not written by Brendan Behan or his brother Dominic but by a friend of Brendan’s called Dick Shannon

The best version of the song I’ve heard is by Damien Dempsey and Glen Hansard. Which appears on Damien Dempsey album It’s all good: The best of Damien Dempsey.

Just a little note to add to your article. I sang the song on the soundtrack of the movie.and later in 1961 met up with and made friends with Dominic Behan and his wife at the Edinburgh Festival . He was asking all the folk singers he met if they knew who, he thought, had ruined the song. He thought he should have sung it as the great man's brother and as a claimant to the writing oi the song itself.
He was so full of frustration and anger I did not dare tell him I was the culprit. Ian McCulloch- nothing to do with Echo and the Bunnymen!