I'm a huge fan of the Chilean Seabass on SQ. Fell in love with the in-flight menu version of it on my first business trip 2 years ago and have ordered it at least a half dozen times since then - I would highly recommend it. Here are some pictures for your reference:


Pan Roasted Chilean Bass served w/ creamy ginger sauce
SIN-NRT: May 2011 (SQ J In-Flight Menu)


Grilled Chilean Seabass
SIN-HKG: Dec 2012 (SQ J BTC)


Grilled Chilean Seabass
SIN-PVG: Dec 2012 (SQ J BTC)

My experiences with beef on SQ (both BTC & in-flight menu) has been mixed, similar to what others have mentioned. About half the time it is tough and not nice, but the other half of the time it's quite good. Here's a particularly delicious one that I had in August, which rivals some of the better steaks I've had in SG restaurants:


Grilled Beef Filet w/ mushroom gratin, red wine sauce, asparagus and fondant potatoes
HKG-SIN: Aug 2013 (SQ J In-Flight Menu)