We'll need to know when you are thinking of going so we can pick a place based on the weather patterns. In terms of beaches the ones in Thailand tend to be better than those in Malaysia, although Langkawi has some nice ones (Datai and Tanjung Rhu for example and there are some nice beaches to be found on Borneo). Penang has plenty to do but the sea can be a nice shade of grey.

If you are looking in our winter than the beaches of Thailand - Phuket or Krabi for example are well worth a visit - plenty of things to do apart from beaching. In the summer months perhaps Koh Samui would be a better choice.

We were in Penang a few years ago, and whilst the beaches look nice, because of the jellyfish they were completely deserted, sio I would give that a miss if a good beach is what you are after.

Sunbear is spto on with Langkawi and the Datai! Langkawi is a beautiful island with great people, great restaurants and great beeches. There is plenty to do for 7/10days. Car Hire is definitly worth it and the island is VERY easy to drive around.

Also worth combining with KL. Malaysian Airlines offer free stop overs so with only the hotel to pay for then why not!!