I've been twice to Busuanga (Sept 07, and Oct 08), and my resort of choice is Sangat Island Reserve, it costs around 8,000 pesos per night for 2 people but its worth it if your budget stretches this far. Included is transfers to and from airport and all food, served buffet style (excellent). There is no aircon, tv, fridge, and electricity is on only from 6pm-6am but for me that isn't a problem and allows you to concentrate on being on a remote island. The beach is great, as are the staff and the whole place feels like its very well run. Kayaking is free and its fun paddling to the hot springs through a mangrove forrest and stopping off at snorkelling spots on the way. They also have a diving shop and i highly recommend trying the wreak diving.
On my second trip we also stayed a few nights on Busuanga Island to save some money and see what it has to offer. We stayed at Kokosmuss Resort which gave us a decent aircon and tv room with nice bathroom for 1600 Pesos. Its not on a beach, but is good value (watch out for dog muck if playing volleyball on their lawn though). From here we did the Coron Island day trip which is the best boat trip I've done in Palawan- exotic lakes, amazing beaches, lagoons- pure paradise! We also hired a motorbike for a day- this is often something I like to do on small islands but was a waste of time here- we travelled all day on a gravel road and just saw one waterfall. Check out Bistro Coron for excellent steaks, I ordered 2 as they were good value.