I think Singapore Airlines is one of the airline with best finance, as it is profitable every year since early 1980's, even when Cathay Pacific is losing money in 1998-99 Asian Economic Crisis.

I think many European fully state-owned airlines, like TAP Portugal, Iberia, Alitalia, Air France, Olympic Airways, are the airlines with worst finance, loses money every year and needs billions of US Dollars of Government subsidize every year.