Originally Posted by
mister__big
I always recommend going with the FFP of your most travelled carrier. In your case, I'd recommend SQ if you mostly fly SQ, even though SQ gold is pretty lousy.
Sometimes airlines will reward travelers who have shown loyalty to them over the years, so bear in mind that if you hop between FFPs, you won't be eligible for these rewards (if any).
I must be one guy who departs from this rule. I travel most on SQ, but log all my miles to TG ROP, for reasons that it is so difficult to get redemption flight on SQ, and other benefits are as good as non existent.
I can get lounge access from any *Alliance FFP, and GUP on TG costs me no mileage.