What about Australia? Between Marriott and Starwood there are a number of options to choose from.

While I've never been to Thailand myself, my daughter just got back from a month there with a bunch of friends hiking around the country and staying at very inexpensive (i.e. non-Marriott) hotels, but she thoroughly enjoyed it. And she loved the scenery. There have been a lot of FTers posting very positive things about the resorts there.