Boracay is quickly gaining a reputation as a tourist trap, but I'd still recommend it for someone who has never been. The nightlife and beaches are great. As Mr. Roboto stated, the best time to go is from November to March. Personally, I like to do Boracay in the first week of January. March to June is the hot and dry season. The beaches will be crowded as school is out. The beautiful, clear water takes on a greenish tint from the seasonal algae. June to October is rainy and there is the risk of typhoons. It's no fun being trapped on a small island during a major storm.

Palawan is a nice destination. It's a bit cheaper than Boracay and the beaches aren't as crowded. The fares from Manila to Puerto Princessa are typically dirt cheap via Cebu Pacific.

Baguio is great for a 1-3 day trip. The climate is uncharacteristically cool and the air is clean. It's a short flight from Manila or you can reach it by car or bus in about 5-6 hours. We actually prefer to drive just to enjoy the scenery and mountain views.

Tagaytay is another nice, cool place to escape. There are hotels and inns that offer privacy at an affordable price. Taal Volcano is a local tourist site and is considered the smallest active volcano in the world. The Taal Tours are a major tourist trap, probably the worst I've encountered in the Philippines.

I can recommend many more. There are lots of nice resorts right here in Luzon. Some of them aren't as widely known as the famous spots, but are just as nice.