weejoe, it's starting to get real hot in malaysia now. i dont think there'll be much rain for til the end of this year.
u can consider pulau tioman, near the southernmost state of johor (just a bridge away is singapore). the best beach on tioman is salang. i can give u recommendations to accomodations if u want. if u stay long term, u can get pretty good discounts.
how much budget do u have?
u can go to johor and go around the city (not much to see though, i should know cos i live here) or to singapore (well, it's another city, all too familiar to me to seem interesting at all, but i've been told that many tourists love the place)