Above about Pantai Chenang.
A beautiful beach, with beautiful nature and beautiful people. This beach is the center of the action and adventure in Langkawi are, i think. You have the opportunities to try jet ski, parasailing, and for family, you can try the banana boat. I think for the local here, the price is quite steep, as for 30 minute ride, you’ll pay RM90 minimum for jet ski and parasailing. Maybe for the foreigners is quite cheap, don't know. Try asking them.
And at night, the beach is quite dark, but there a few place to hang out at beach