If measuring such a thing were even possible.
This bold claim was made according to the votes of more than "60 artists, journalists and music industry executives" based on this performance from Live Aid in 1985. Utterly "Dionysian," according to one critic. But what must've really piqued their pointy heads were the sheer numbers of clapping hands and ringing voices from this audience of 75,000. Watch as they go ga-ga along with Freddy in this video compilation of some of the greatest moments from the Greatest Live Performance, etc:
I myself saw Queen onstage during their Day at the Races period. Hearing Bohemian performed to a taped chorus, even with Freddy fronting, was less of an experience than I was hoping for. I thought that even a truncated version of the song would've been the better choice. Other bands of the period that attempted touring with large ensembles, such as orchestras, found themselves quickly going broke. Taped, quasi-Karaoke presentations pale in authenticity even when compared to Vegas jukebox fare like "We Will Rock You". In doing this Freddy presaged generations of canned performances soon to follow: e.g. the mall tours of Debbie Gibson and Tiffany and the virtual singers Britney Spears and Kanye West. By then onstage spectacle obliterated the musical shorthand. A couple of years after my Queen experience a friend would drag me to see Beatlemania. (For those who don't remember: Beatlemania was a live re-creation of Fab Four music played by four musically inclined actors/acting inclined musicians in period costumes all standing before a projected back drop of dated newsy memes. The version I saw even had Paul look-alike playing left hand bass.) The lesson of Beatlemania's success was that however off the mark the show was musically, it was a live performance first and foremost. In Beatlemania's case, it was as close to the real thing as most of us would ever get. The live performance aspect also gave the music a certain amount of heart, however forced, which was just enough for audiences needed to buy the premise. Not long after, MTV's Unplugged would offer even more proof: Audiences crave authenticity, even if it comes by standards less than they remembered. (The post-classic Rolling Stones figured this out a long time ago.)