Marina Bay is located near Sands Bar, so I recommend coming here after a couple of drinks at Sands Bar. It reminded me of the Darling Harbour at Sydney where we usually stay (near the four points hotel). Nice and quiet, with a lot of couples taking pictures and being romantic and all that mushy stuff. Nothing too special here, just another nice stroll with a great view of the Singapore in background.
I would say come during night, but I am more biased because I am a night light person. If you have a girlfriend, bring her here! It’s nice, quiet, relaxing and not crowded. Really great to be all lovey dovey during this time haha.