I have been to Thailand (Krabi) and the Maldives, I preferred Thailand as you get to see lots more culture and it's still nearly as stunning as the Maldives if you pick the right place.
The maldives was quite literally mind blowing but if you don't like snorkeling or diving there isn't much else to do.
Thai people are soooooo much friendlier too, and it's usually genuine.
We were asked to go out with one of the restaurant staff and her family one night, we went in their little pick-up with all of their friends sat in the back bit

I will go back to Thailand as soon as I can but don't have the same desire to go back to the Maldives