I'd pick the daytime departure for leisure travel. Enjoy the wine, food, and service...have a couple naps and then straight to bed when you arrive in SIN.

I've done daytime departure the last 3 trips to Asia...YVR-ICN-SIN on SQ, and twice on NH LAX-NRT and then onto BKK. I get very little jet-lag when I do it this way.

My next trip I'm doing a midnight departure on SQ LAX-TPE. I picked that flight to experience New Business on the 77W. Unfortunately SQ made a sched change and cancelled the flight I was on and re-booked me on a flight the next day with old business class. Although I save a hotel room night by flying overnight, I think I will arrive quite tired after an almost 15 hour night flight that arrives at 6am in Taipei.