Love the Hong Kong airport, their primary hub.
I never got to fly Singapore, but everyone who has flown them, without exception, has told me Singapore was better than even Cathay, so they must be pretty damned good.
Japan Airlines, Korean Airlines...also very good.
EVA Airlines (Taiwan) I only flew once and it was a nightmare flight. Maybe it was a fluke, but I never gave them another chance.
SAS, British, Lufthansa were always decent enough.
Domestically, I don't have a preference. But I never fly a US airlines overseas if I can avoid it.
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