first of all,what is your budget?well,if u gonna visit kl first,then i`ll suggest langkawi.nice beautiful beaches with laid back atmosphere.i`m sure after u visit kl,u`ll wanna go somewhere more relaxing.cpls of nice htls in langkawi,but then again depending on your budget!tanjung rhu,casa del mar to name a few.(www.tripadvisor.com)click on langkawi,penang or kl,and it will give u some information regarding the property and reviews from previous travellers!in kl,i would recommend grand maya.(nice boutique htl,close to twin tower.or ritz carlton.go to the site,and perhaps u can make your decision then.!if u have any other question,pls feel free to ask!
good luck
ratu