I am sure this is a topic that would generate a lot of debate, but some have had a go at choosing the best wines in the sky. From a NZ article:
If you're looking for the best wine in the sky - and especially if you like local wine - you'd probably be better off flying Singapore Airlines or Air New Zealand. Or, if you don't mind drinking Australian wines, maybe Qantas.
In the latest Cellars in the Sky Awards, run by Business Traveller magazine, the best white served in business class was judged to be the St Clair Marlborough sauvignon blanc offered by Singapore. And the best red was the Pegasus Bay pinot noir served by Air NZ.
The same two airlines were also joint runners-up for the best sparkling wine with French champagnes.
Of other airlines flying here, Cathay Pacific picked up a second-place for the Monterey chardonnay it serves in business class, Emirates got a couple of mentions for the wines enjoyed by its first class passengers and Qantas got a stack of awards.
Qantas was judged to have both the best business class cellar overall - with Air New Zealand runner-up - and the best first class cellar. The wines served in economy class were not considered.