OK I'll bite

British Airways
Lufthansa
Air China (SP)
All Nippon (SR)
All Nippon -400
Cathay Pacific
Korean
Asiana
Singapore
United

An interesting question

TWA
AA
BA
Cathay
Singapore
Malaysian including LHR to Lankawi direct
Qantas (inc upstairs !!)
Air NZ
Fiji Airways
United
Virgin

I may have missed a few.

PA TWA BA AF SIA LH KAL KLM UA Air China

Not many for me:

BA
Cathay
Virgin

For me
BA
Cathay Pacific
TWA
Singapore Airlines
Malaysian
Virgin
Air New Zealand

BOAC/BA
Iraqi Airways
Air Atlanta
SAA
SIA
Cathay Pacific
Air China
ANZ
Garuda
Swissair
KLM
Varig
Thai Airways
Qantas
MAS
United
EVA
Asiana
Lufthansa
British Asia

Aaaaah!! BOAC

BA
Virgin
TWA
KLM
Canadian
Air Europe (Air Europa?) from LGW. Leased Pan Am aircraft to Puerto Plata. An interesting destination, the climb up the steps seemed like scaling Everest. As for the baggage reclaim, that’s another story! Circa 1988/1989.

As a passenger the 747 was probably the worst aircraft I ever flew on. 1998. Continental London to Philly (iirc). The aircraft was old, cold, noisy and antiquated. The earphones where just hollow tubes.
Having said that as an enthusiast it's my favourite aircraft. Great noise. Great look. A beautiful aircraft.

Went to Jamaica on an Aer Lingus one leased to Air Jamaica

Sounds like europe !!!!!!!!

Best 747 flight- UA ORD-SFO Christmas Day 1980. Cabin crew outnumbered pax, and I took the 750 ml liquor bottles in the upper deck bar as a personal challenge.
Worst 747 flight- SABENA BRU-JFK in 1974. Waiting in BRU for the return to the US, announcements said about an hour delay when the equipment hadn't left JFK yet. When finally airborne, found out potable water hadn't been serviced, before we knew you shouldn't drink it.

OK, not including various Boeing related flight tests and ferry flights on 747s:
TWA (two of the most horrible flights I've ever had on a 'Western' airline)
United
Pan Am (got upgraded to First Class - the most incredible meal experience ever in the air)
British Airways
Singapore
Korean
EVA
Malaysian

SABENA = Such A Bad Experience Never Again!

Pan Am, BOAC (staff travel to SYD return), BA, Virgin, JAL, Air India (LHR - JFK)

Tight seating A300B, DC-10 and 767 could be much worse.

Besides the "standard airlines" as pax , I had the pleasure to jumpseat a few times on B747-200F ( Martinair ) and 747SP ( China airlines , LAX-TPE the direct flight when you lost one day on the trip .) and a few years ago a surprie jumpseat on the Iran Air 747SP , due to an AOG on one of their A300. One of the oldest 747 still flying at the time ( they only retired it very recently if I am not msitaken ) . While 747 cockpits were noisy and very small compared to other wide bodies of that era ( e.g. DC10 and L-1011, ) jumseating on them was a real pleasure because of the huge space avail behind the cockipt , usually equipped with a bar/galley and (old) first class seats .

Or a crowded DC-8.

The AC 747 between YYZ and YVR was wonderful. Now you'll do the same 4hrs trip in a jam packed narrow body. That's progress. :mad:

BA (first flights BOAC)
Singapore
Qantas
Japan Airlines
TWA
Thai
Air France
KLM
Lufthansa
Virgin
Probably forgotten a few, but memorable were the upgrades sitting at the very front on BA and Singapore. Anyone who considers them bad from a passenger perspective is an outlier although I accept the middle of a row at the back would not be ideal.