I have to agree with kaikohe76 on best and worst airports. Changi is superb, apart from the distances. They will even take you on a free city tour if you have more than five hours to spare.
Bangkok is on a par with Changi but Singapore has the edge.
LAX - yeughh! What a dismal place to be stuck, surly staff, poor lighting, lousy shopping, I could go on.
I once waited in front of an American Eagle desk at Vegas McCarron, whilst the clerk hummed and typed and check bits of paper for ten minutes without ever looking at me, before saying "I'm not ignoring you sir" He did a really good impression of someone who was!
Best Airline IMHO is Singapore Airlines, very attentive and punctual
Worst Airline, Hawaiian Air. Spent an overnight flight from Honolulu to LAX with nothing but a cup of water and a cheese roll for service.