Hi

I've never been to Singapore so can't help you there - but we went to Phuket for a big family holiday in 2008.

We went with MIL, FIL, Bil & his wife & their 2 girls (plus my DS who was 9 at the time & other BIL who was 15)

We stayed at the Patong Merlin & they were fantastic.

From what I can gather, anywhere in Phuket is really family friendly - they are just so welcoming there of little ones.

The rooms were no oversized, but more than big enough (my 2 nieces were 1yrs & 3yrs at the time) - although I can't remember now if SIL took the portacot or if the hotel had one
There was enough room for their double bed, a single for the 3yr old & the portacot though.

They got an ajoining room to MIL & FIL so when we went out a few of the nights, MIL just opened the door & were able to watch the kids & not have to move rooms.

Plenty of things to do for family (with the pool, etc, they had a smaller pool for little people as well as the bigger ones) - and the menus & buffets had a wide enough range for adults & kids.

Its pretty central to everything as far as shopping/places to eat etc as well.

HTH & have fun!