the area next to the narrow pedestrian bridge opposite the Changi Village jetty to Pulau Ubin - can see planes too. but its still better to watch from Nicoll Drive around Carpark 3 area.
along changi coast rd, saw people like to park their veihcles next to the emergency exit gates to watch the planes take off. however, can be summoned by the police that frequently patrols there. there's a carpark along this road where you can park your car and then cross over the road to see the planes which i think would be better.
i'm very disappointed with the new Changi Airport. In the past, the viewing gallery in Terminal 1 stretches all the way to the end and further extends another 50m to the left, where the old Swensens used to be located. Now, its like s*hit and the check-in area further blocksthe view from those standing at the viewing gallery. For Terminal 2, the original design for the viewing gallery was really suberb. but now, its a total disappointment! There's no more viewing gallery!