Singapore Airlines is probably the best airline in the world for personal service. I wouldn't pay that much of a premium though. British Airways (if you can put up with their flight attendants) and Virgin (if you prefer to be more informal) both fly to Sydney
If price is your principal driver, I'd go with any of the major airlines.
By the way, as a brief anecdote about British Airways: I was waiting for a connection in Gatwick Airport about a year ago. An African lady was obviously confused about the gate for her flight and asked the BA counter agent for help. Rather flustered, the poor lady took off in the wrong direction. In typical BA fashion, the counter agent shouted to her at the top of her lungs: "Come back, you stupid woman. You're going the wrong way!" Needless to say, everyone within hearing distance turned their heads to see what was happening.
A few minutes later, I went up to the counter and corrected the agent, telling her - in no uncertain terms - that if an employee of mine ever acted so rudely, she's be fired on the spot. The agent and her colleagues became very defensive, clearly surprised that someone would pull them up for doing this. Maybe this extreme example is not the norm, but I have encountered several instances of BA staff behaving rudely, arrogantly, and being unnecessarily overbearing. It's such a shame because BA is one of the more reliable airlines.
