Anyone been to Thailand?

[Ruth]

I am just about to book and pay for a vacation package. At first I was going to go to Bali but have heard and researched some conflicting reports about how touristy and crowded it is and so decided to switch my destination to Thailand. I am pretty sure I am going to go to a place called Koh Tao as I want to have some relaxing time on the beach as well as take a PADI diving course. Of course a couple of days in Bankock for the manditory shopping.
Has anyone been here and can you tell me anything about more about it?