Of the well-known brands or companies with money-changing services in the Philippines, Villarica Pawn Shop offers the highest rates in USD-PHP currency exchange.
SM and its sister companies such as SM Hypermarket come close.
But aside from the rate, here's another thing to consider though. SM is a much bigger place, so you'll feel safer there. Villarica has many branches, but you need to consider where they're located.
Also, it helps if your preferred money changer is near your bank so you can immediately deposit your money and go home without the burden of carrying a big amount of cash.
Bring your ID. They'll look for it.