The best IMO is Qantas via Singapore because the break in Changi is really good. Hands down the best airport out there, with pools, and the waterfall.
Second best would be Qatar via Doha. It's also a good airport, although not as good as Changi, and it also cuts badly into the long sleep.
Third together, BA via Singapore and Cathay via Hong Kong. Cathay is amazing, and it is going to be the A350 which is just so comfortable, but I personally don't like Hong Kong airport. BA via Singapore is the other way around: poor passenger experience but the airport is great.