Good yet another member flying to Singapore.
I am biased, so I would advice you to go SQ. They treat Caucassians extremely well, so you are in for a top notch service. I am not sure about the newer economy classes as the last time I took SQ was in June last year.
Hmm, I don't know about SQ. My friend (yes, he is "caucasian") just came back from Asia, flew SQ 744 LAX-TPE on First Class and did not believe SQ was as hyped-up as it was said to be. Flew CX (Cathay Pacific) HKG-LAX on their new 744 F product, and was blown away. He said he will give SQ another try on their A380s, but until then he strongly recommends CX as the carrier of choice to Asia (yes, he is a picky, seasoned traveler). At least on Airliners.net, CX vs. SQ is like Mac vs. PC debate!
As for myself I am virtually enslaved by American Airlines. As AAdvantage Platinum, it's not like I really have a choice, though, and it's not too bad (periodic complimentary upgrades are nice), and at least I can bypass most of the long check-in/security/boarding lines.
I did fly Virgin America LAX-JFK back in December, though, which was phenomenal. I was planning to fly AA's 767 widebody service, but I thought I'd give VA a try. Very impressive product, though the plane (only an A320) was literally 1/2 empty, and I don't know how they expect to survive in the long run. I had the entire row to myself (as did most other people), which made the flight just as comfortable as First Class, save for the food.
iMacZealot, sorry I did not notice your post! It depends, I don't know if UA will have rolled out their new J Business Class product by then for DEN-SIN (if so, it is very competitive and impressive). I'd still pick J United over Y SQ because any extra space will be nice (and if you can afford it), although SQ service in Y will be much better.