If you can afford it, go 65... Trust me. I'm in 4 room with a 55 and looking to upgrade to 65..
LAGI best if 75...
75" is just asking to get chopped given singapore prices =/
The C9 77" US model can be had for 3500 - 4000 USD (eg: newegg has it for 3799 now) which is ~5k sing
don't know how they managed to mark up the price to 15k SGD here