Things to do in Thailand:
Go to Lumpinee or Rajamadern stadium in Bangkok- Two of the most prestigiuos Muay Thai stadiums in Thailand...Best exhibition of Muay Thai in the world....
Visit Khao San Road - See a lot of dirty hippies but there's a lot stuff to buy and places to eat....One of the most touristy places in Bangkok...Good place to go to buy gear for travelling especially for the beach (sandals, beach wear and surfer shorts)
Chiang Mai - Second biggest city in Thailand but it feels like a laid back town...Sunday Market in the old city is one of the most popular arts and crafts (and biggest) bazzars in Thailand...
Beaches - Koh Phi Phi, Koh Samui, Phuket....Plenty of choices for island and beaches....Suntanning, Swimming, Surfing, Snorkeling, Sightseeing etc....
Sports - Go to a Muay Thai Camp and train Thai boxing....Don't have to ever have done it...A good camp will have a Pro Thai trainer work with you for the whole time you're there....
Shoot some guns....Chiang Mai and other cities have police and army gun ranges where you can shoot a wide variety of guns....Pretty damn fun....
And Golf---Can't really comment much about that since I hate Golf...but I do know they have a lot of Golf resorts...
Food - Plenty of places to eat everywhere....and a wide range of foods from all over Thailand and all over the world....You could go to certain places in Thailand for a year and wouldn't have to eat a Thai dish once if you didn't want to....A full meal can cost as cheap as a dollar or two....
Historical Places and Temples - Plenty of temples all over Thailand (called Wats)....Doi Sui Tep in Chiang Mai is one of the most famous ones located on top of a mountain....Plenty of historical monuments dating back from the Kingdom of Siam....
Spas and Resorts - Some of the best spas in the world....Go for Thai Massage...One of the best massages in the world....
Shopping - Plenty of shopping from clothes to electronics to Pirated DVDs (of TV shows and movies) and music cds, etc.....Bangkok would be the best place to shop.....MBK is one of the best places to go....Or if you really want to spend money go to the Paragon - Bangkok's most expensive mall (kind of a Yorkdale if it were a mall) - Has a Lamborghini and Ferrari dealership in it....
That's all I can think of for now (fucking tired - its late)....