Based on online recommendations, Edzen seems to be one of the best money changers in Manila. It is quite obvious that it has a large stock of euros as publicized by the Euro general scandal. Edzen Money Changer is located in Mabini Street, between Pedro Gil and Salas Street. If you don't like Edzen, there are other exchange centers looming around the place.
The problem with Manila though is that it is a very unsafe place to carry around money. Since I didn't want to die of paranoia I decided to buy my euros in BPI Forex 6750 Branch. It is the best option for me since I have a BPI account. Instead of carrying around cash, I only had to fill out a withdrawal slip and hand it over to the teller. After few minutes of waiting,...voila! The pesos are now in euros.
At the time of my transaction, BPI rate was 1 EUR= Php 64.0827.
Aside from BPI Forex, I also recommend iFX Foreign Exchange Center. It is located in the lower ground of Goldcrest in Glorietta.