Planning vacation in thailand

Planning vacation in one of thailand famous islands should i go to Phuket, Ko Samui, Ko Phi Phi, Ko Pha Ngan, Ko Tao, Ko Samet i cant decide, i already have been in Ko Pha Ngan but i dont want to party ijust want to relax and have a internet conction available…. and any way there are Too many islands, too little time!!! can somebody help me choose one???