Winds are so variable, there is no best side.
If you take from 16R, the normal SIN flightpath means that you will be 5,000-10,000 feet high and about 20-30kms from the harbour as the plane makes a right hand turn and heads out over western Sydney.
If you take off from 34L, the normal SIN flightpath means that you will take a slight left turn shortly after take off and even if you sit at the window your view of the harbour may be obscured.