Krabi / Koh Lanta / Phi Phi or Koh Samui in April?

Krabi is nice. A lot of beautiful cliffs overlooking the water, perfect if you want to go rock climing. The islands off Krabi also have beautiful beaches. Krabi is probably the least crowded compared to Phuket and Koh Samui. I personally got sick of Phuket, way too many tourists. Koh Samui is good too. If you want to try something new, try Koh Chang, not many have heard of it and it is in the eastern part of Thailand (3-4 hours drives from Bangkok). Last time I went there it was empty, shared the whole beach with like 5 other people, it was great, very peaceful.