I think it’s unfortunate that most people land in Bangkok for their Thailand visit/trip. It’s a terrible choice to begin a Thailand tour, let alone one that defines the country. Real Thailand lies beyond Bangkok. I know you can’t avoid Bangkok if you are visiting Thailand but you don’t have to waste any money in this city. You can spend a couple of hours at the Grand Palace and the Khaosan road. You can also check out the infamous Nana Plaza and Soi Cowboy if you must. But that’s about it. If you manage to escape the hell that’s Bangkok the same day you arrive, consider yourself lucky.
You can leave for the islands in the south or Ayutthaya, the ancient Thai capital, which is just one-hour away. As they say in the tourist-slang: do anything but Bangkok.