We only stayed one night ,but we found the Khao Sok Palm Garden resort to be excellent! The bungalows are nice and clean and are located away from the main road so it is nice and quiet at night. The shower in our unit (#4) was by far the best I've had in Thailand!
The couple running it are so kind and helpful. We booked a one day lake tour through them and when I got food poisoning the night before the tour, they happily refunded my ticket and even gave me a ride in their personal vehicle to my next accommodation.
Definitely recommend staying here!