The consistently worst airline for me was United (I was regularly commuting on BA, SQ, Cathay, United, Qantas, JAL and Garuda), one example in business class the passenger next to me was using her computer when her meal arrived , a large grumpy faced lady flight attendant said in a loud and very rude voice "move yer stuff !" and then half dropped the meal tray onto the table in front of the passenger, not on I'm afraid.
Qantas is a mid fielder now in terms of economy cabin crew service. 20 years ago they were one of the best. If I've purchased a discount economy ticket I don't expect to be treated like a king but Qantas service in business class is still very good.