Strangely, the answer to this question, for me, is BA! Let me explain.
Back in 1983, whilst fulfilling my obligations to HMQ, BEagle's so-called Vickers Funbus mob failed to provide the necessary and promised ac to move 16 Sqn from Laarbruch to Cold Lake to participate in Maple Flag. Following a necessarily short exchange (we got no more than 48 hours notice of a lack of assets) between OC 16; HQ RAFG and (was it?) HQ 46 Gp the decision was taken to fly the aircrew civair to allow them to acclimatise before taking on the elements and the bad guys at 100 ft. This was in the days when BA still asked for payment for booze whilst travelling in cattle class on long haul! After a very pleasant Lufthansa flight to LHR with complimentary G&Ts, I and 25 fellow aircrew boarded a Jumbo bound for Toronto seated as far back as possible without actually being in the cr****rs. As we lifted off the tarmac, each with about 7 or 8 G&Ts now swilling internally, the trolley dolly announced to one and all that because they had members of the esteemed BA Canada Club travelling, all drinks would be courtesy of BA - Mistake!
One hour out from Toronto back she came on the blower to apologise that, because their hospitality had been so welcomed, they had run out of booze!! Well, she added, not exactly run out, they had Tia Maria left and if anybody fancied a Tia Maria they should ring their bells now.
Needless to say, she had hardly uttered the words when 26 hands at the back of the aircraft were raised to the ceiling! The ac landed dry at Toronto.
Once happily in our Club seats on the Air Canada 727 and half-way to Edmonton later that day, we were surprised to hear that the chief steward felt obliged to close the bar because some of his passengers had clearly had too much to drink already! Who? Us!
So for me - it's BA but, I have to say for levels of comfort and attention Singapore Airlines Raffles Class to Melbourne many years later runs a very close second!