(Honourable mention 1 - Live Aid '85, although it was a charity show with dozens of bands on the bill)
(Honourable mention 2 - Kharkov '08, where Queen + Paul Rodgers played to about 350,000 people)
Top 10 most bootlegged Queen concerts (not including officially-released shows):
Tokyo 3-31-76
Tokyo 4-1-76
Seattle 3-13-77
London 6-6-77
Cologne 2-1-79
Leiden 11-27-80
Buenos Aires 2-28-81
Fukuoka 10-19-82
Fukuoka 10-20-82
Mannheim 6-21-86
Top 10 unofficial Queen concert recordings from the 70s, quality-wise:
Boston 1-30-76 - 24bit/96kHz transfer from master cassette
Boston 2-9-77 - master cassettes > reel
Inglewood 3-3-77 - Mike Millard Master Cassettes > Yamaha KX-W592 Cassette Deck > Sony R-500 DAT > Analog Master DAT Clone > Fostex D5 DAT > Sound Devices USBPre 2 > Audacity 2.0 capture > iZotope RX6 > iZotope Ozone 6 > Audacity > TLH > FLAC
London 6-6-77 - best video source
Houston 12-11-77 - best video source
Long Beach 12-20-77 - Mike Millard Master Cassettes > Yamaha KX-W592 Cassette Deck > Sony R-500 DAT > Analog Master DAT Clone > Focusrite Scarlett 6i6 > Sound Forge Audio Studio 13.0 capture > Adobe Audition > iZotope RX8 > iZotope Ozone 8 > Audacity > TLH > FLAC
Providence 11-14-78 - master cassette
Chicago 12-7-78 - master cassette
Tokyo 4-14-79 - "Bootleg Race" (Tarantura)
London 12-26-79 - "Hammersmith Odeon 1979" (Wardour)
Top 10 unofficial Queen concert recordings from the 80s, quality-wise:
Oakland 7-14-80 - third generation cassette
Rosemont 9-19-80 - master cassette
Tokyo 2-16-81 - "The Miracle Game" (Tarantura)
Buenos Aires 2-28-81 - soundboard > reel > cassette (2)
Sao Paulo 3-20-81 - "Morumbi Stadium 1981" (Pablo)
Nishinomiya 10-24-82 - AUDIENCE ANALOG SECOND GENERATION (24/96)>NAKAMICHI DR-1 W/MANUAL AZIMUTH ADJUSTMENT>CREATIVE SOUNDBLASTER X-FI HD MODEL #SB1240 WAV (24/96KHZ)>MAGIX AUDIO CLEANING LAB FOR KRW>TRACK MARKS VOLUME ADJUSTMENT AND EDITS>WAV 24/96>TRADERS LITTLE HELPER FLAC (LEVEL 8)
Birmingham 9-2-84 - master cassette
Sun City 10-19-84 - soundboard recording
Osaka 5-15-85 - "The Last Concert In Japan" (Masterport)
Mannheim 6-21-86 - "Queen Reigns The World" LP
Top 10 Queen performances, musically-speaking:
(naturally a very subjective category, not least because it depends on the existence of good enough sounding tapes that still may not capture the entirety of a show's atmosphere)
Tokyo 5-1-75
Boston 1-30-76
Inglewood 12-22-77
Copenhagen 4-13-78
Newcastle 12-4-79
London 12-8-80
Buenos Aires 3-8-81
Leeds 5-29-82
Tokyo 5-9-85
Stevenage 8-9-86
Honourable mentions of significant shows and recordings:
London 9-13-73 - early radio broadcast in great quality
Liverpool 11-17-73 - fantastic early document of the band, including the non-album track 'Hangman'
Portland 4-28-74 - great recording of the band on their quest to conquer America
Tokyo 4-19-75 - Queen's first reaction to their Japanese fans
Yokohama 4-30-75 - a recording on par with the classic following night in Tokyo
London 9-18-76 - audience recording debunks many myths surrounding this important show
Seattle 3-13-77 - one of the best documents of the Queen / Thin Lizzy tour
Copenhagen 5-12-77 - essential A Day At The Races tour recording
London 10-6-77 - Queen perform an informal and unique show
New York 11-17-78 - classic show, with strippers riding bikes on stage during Fat Bottomed Girls
Montreal 12-1-78 - an incredible atmosphere captured on a brilliant audience tape
Vancouver 12-14-78 - another essential Jazz tour tape
Rotterdam 1-30-79 - some of Brian's best live guitar work caught on tape
Frankfurt 2-2-79 - many parts of Live Killers revealed here
Lyon 2-17-79 - and here
Paris 3-1-79 - epic final night of the Live Killers tour
Milwaukee 9-10-80 - essential listening from Queen's US peak
Puebla 10-17-81 - Queen vs. many projectiles
Leiden 4-24-82 - one of the best audiences ever
Sapporo 10-29-82 - many interesting versions of songs played, including a rare full version of Teo Torriatte
Brussels 8-24-84 - a truly brilliant vocal performance from Freddie
Birmingham 8-31-84 - almost certainly the overall best performance of The Works tour
Stockholm 6-7-86 - energetic opening night of the final Queen tour