I agree with Itim, Shake, Rattle and Roll (at least the first segment), and Patayin sa Sindak si Barbara. I'd throw in at least one segment in one Shake sequel (I liked "Ang Witawit"), The "Ang Kuba" section of "Magandang Hatinggabi." Pa Siyam is visually and tonally pretty good, tho emotionally and dramatically a tad simplistic.
I'd also add O'Hara's Halimaw sa Banga, a great little short segment with a remarkably complex story between father, stepmother and child in the foreground and the ominous hint of a war between angels in the background. And O'Hara's underrated, little seen Manananggal in Manila, an ambitious script yoked to a terrible no-budget production where the people and even the monsters when they eventually surface are not what they seem.
Then there's the De Leon segment of Fe, Esperanza, Caridad, easily the best of the three, and one of the best shorts involving the Devil that I know of. And De Leon's great Terror is a Man--a moody, visually and dramatically complex retelling of The Island of Dr. Moreau.
And maybe my favorite Filipino horror film--but then it's so much more as well, a love story, war picture, political expose and celebration of Filipino poetry--Pangarap ng Puso. With a real horrorshow ending.