Dawn and sun rise, to me, is the best time to view the Taj Mahal.
Make your way to the Taj early in the morning, around 5am, and
walk to the Yamuna River, turn right upon reaching the gate to the entrance of the Taj. The walk is approximately 1 km.
Take a boat ride across the river and sit there, just gawking and gaping at the Taj. That's what I did! For almost 3 hours....... :P
And best of all, other than the boat ride, everything is FREE!!! No entrance Fees required!
But then again, of course, one must still nevertheless, make a trip within the wall of the Taj (tix @ Rp500 ea for foreigners) just to admire this miraculous testament of love....