Puerto Galera diving is ok. Verde Island just off PG is better for reef life but don't expect the same pelagic life as Palau by any means. There is nice wrecks and deep reefs that require tech diver qualifications. If you are a single man, you'll like the nightlife (seedy).
If anything, I definitely recommend Anilao/Batangas over PG anytime for diving from Manila. Much better life (macro) and there's actually a school of maybe 1000 trevally at the Dive N trek house reef. Cathedral is a very nice sight as is the muck diving at Basura. There are a bunch of dive resorts there and the macro diving is as good as PNG. It's only 2-3 hrs by car and without the boat ride to PG.
If you have to go to PG, I'd stay at El Galleon and use Asian Divers. It's a further away from the sleezy nightlife of Sabang Beach.
Similan, Ko Tachai, Bon and Richelieu are better for fish life, especially pelagics like whalesharks (though by no means a regular occurrence) and mantas, but don't expect too many other sharks. The corals around Similan are very pretty. As for Tubataha, it's nice but fished out by shark finners. You get white tips now and then.
Palau has the reef sharks in numbers due to their conservation efforts. For pelagics, it's a top choice, PG is a nice choice for quick weekend getaway and partying.
Anilao is a top choice for macro.