Hey Vlad,
as I am here each day in the waters around Duamguete, I guess I should give you some suggestions. If you look for BIG stuff you might have bad luck in Dumaguete and Apo. Even I saw whaleshark Manta and Eagle ray and last week a Hammerhead in Apo.
On 2 divespots around Apo are some nice schools of Jack-fish, some giant Trevellis and some Bumpheads around. Also around Apo Clown-Frogfish, blue Ribbon-Eal, Nudibranches, Turtle Seasnakes.
There is a spot on Apo where there are chances to find Hammerheads.
The whole Dumaguete Area is Macro-diving. For that you need the right guide, who knows the area. Mandarinfish can be found in the Sanctuary in front of Atlantis at 17.15 - 18.00. I know it sounds funny, but thats what it is...
The Car-wrecks is an absolute must, I made a post her on DI:
The Car Wrecks
Masaplod Sur is famous for Nudibranches and Crab-Eyed-Goby, but also I nice little Reef.
Masaplod Norte is a lot of Sand with many blue Spotted Stingray and a small little reef in the middle of the Sanctuary.
Dauin is a huge Sanctuary, that you either dive it from the South or North (always as a loop) Nice reef, good change to find some reall special stuff in the south part.
dauin North is just a great Aquarium dive with fantastic Corals in the shallow.
El Dorado housereef is also an Aquarium Dive, quite sandy with colorful coralpatches and many fish-fish. Also quite some Blue Spotted Stibngrays around.
DUCOMI (The Pier) is a must-dive, but as it is private property it needs a special permit (and payment) to dive it.
Mainit is a nice drift dive and if your guide knows where to jump in the water there is a good change to swim in the middle of big school of Baracudas. you end the dive in the middle of underwater Hotsprings.
Hope it helped a bit.
What shop are you diving with? and where do you stay?
cheers
Rhoody