We had stayed at JW Marriott in Phuket for in last November to celebrate Karina's first birthday. It is an excellent resort, each room have a "Sala" area with the message mats, it provides extra space for the toddler to play in the room. The hotel had arranged a lot of exciting activities for the kids, but Karina was too young for most of them. Therefore, we spent most of the time in the pool which were great fun especially with the slide.
I also stayed in Laguna beach before and had stayed in Allamanda, Sheraton and Banyan. But if I go there again, I will choose Sheraton if I travel with Karina and Banyan if just myself and my husband.
Don't forget to try the spa at Marriott Phuket, it is as good as the one in Banyan.