My company conducted the annual summer outing for its employees in Virgin Beach Resort, in Laiya, Batangas. The resort, about 3 hours from Manila by bus, has open-air bamboo cabanas and parasols lining along the 2-kilometer beach.
Useful Info: For a day tour, the entrance fee is PhP 850, including lunch. If you want to stay overnight, the cabanas rent for PhP 5000; the airconditioned 2-bed casitas (PhP 7350, good for 4 persons) are also an option. Directions on how to get there, here. [contact info]