You gotta get up early to see the Big Boy (Is Angkor Wat a boy?) come to life with the rising sun. Say, 4:30am. The main show is at the front entrance, which faces west. Think orange glow, looming backlit behemoth. The crowds gather at a couple of reflecting pools and jockey for position. Proof in this old post here.
It's nice that everyone is fixated on the Instagram angle. It leaves the rest of the temple to the adventurous few. Using a basic strategy of heading in the moment the guards allow it and going straight to the back leaves a bit of time for just you and Mr Wat.
The sunrise results, solitary enrichment.