Thailand, the "Land of Smiles", has so many different and beautiful places & locations that it might be difficult to choose where to go when you are planning your traveling in Thailand. If you like to party the places like Bangkok, Pattaya, Patong beach, Koh Samui and Koh Phangan are THE places to go. And all of this place are easy to reach by air, some even directly with international flight.
If you like to relax and sit on the beach there are many islands and beach resorts in the south of Thailand like Phi Phi Islands, Koh Samui, Krabi, Kata beach, Koh Tao or Koh Lipe. But also not forget the many island along the Eastern Seaboard like Koh Samet (only 3 hours from Bangkok), Koh Chang, Koh Kuud and Koh Mak. Some of this island are "closed" in the windy "winter" season, so check it out before you go there.
But if you like to see nature and/or culture there is a much wider range of choices in Thailand and to prevent you from becoming a Yank that visits Europe in 1 week you should make a choice where you want to go otherwise you will only see the bus or airplane. Arriving in Thailand in Bangkok almost all people visit central-Thailand with in the east-side Kanchanaburi and in the northern-side Ahuthaya and Sukhothai. And most people choose then to go to Northern Thailand or actually North-West Thailand with Chiang Mai, Chiang Rai, Pai and Mae Hong Son. But let not forget the Isaan or the North-East of Thailand with places like Phi Mai, Khorat, Buriram, Surin, Ubon Ratchathani (the gate-way to southern Laos) and Nong Khai (the gate-way to central Laos).
As beaches are not really my cup of tea (although I live about 3km from the sea) and as I think that people who like to party will know where to go I will restrict my planning of travel to "CulNatrual Traveling to the North-West" and "CulNatrual Traveling to the North-East". That will become 2 new postings where I will be traveling along my favorite places.
But both of this journey's will start in Bangkok and when you have never been in Thailand you should take a few days to see & enjoy "the old Venice of Asia" or the more modern nickname for Bangkok "The Big Mango". Most Thai will call it Krungthep. Yes just walk from anywhere into the Skytrain (elevated metro) and buy yourself a ticket to the end. Just sit and watch the changing skyline of Bangkok and the change of people traveling with the Skytrain. Then go to station "Saphan Taksin" (S6) and walk from there the 25m to the Chao Phraya River. Then just take the first "Express boat" that leaves from the ferry pier (buy your ticket at the boat). Just sit and watch Bangkok city passing by with the Wat Arun, Wat Pho and Grand Palace. See the many huge hotels and condos. But they will slowly fade away and suddenly you in real Thailand. And if you are in the express boat with the Green Flag and you will sit long enough then you can get out at the almost last pier at "Wat Klang Kred" (the temple at the channel of the island Kred). This island in the Chao Phraya river is created when they did dig the channel (klong) "Klang Kred" and on new the island were living Mon people from Burma and they started to use the clay for making potteries. And they still do that, and the nice thing is it is a nice small village without traffic. So from the pier take the ferry to the island and just start walking, maybe ask someone to be your guide as there is actually much to see that you would not find yourself. Like a peaceful small temple with a museum and a shop where they make and sell Thai sweets. Going back just take a taxi and take the toll-way. From here you will have again a great view over the skyline of Bangkok. To be honest I think you cannot do this tour in 1 day, so better split it and make Koh Kred and special day tour.
You like shopping? Eat you heart out at "Siam Paragon Shopping Mall" and if you are not yet tired cross the road and visit the many small shops with the new fashions at "Siam Square". Still not tired? Walk to the north side of "Siam Square" and cross the road there to enter "MBK Shopping Mall" famous for its huge mobile telephone department. Or are you more into clothing markets? Then visit "Bobae Market" or "Pratunam Market", but at both be very careful with your wallet.
You like temples & culture? First of all when you visit temples please be dressed polite and behave polite. If you are not religious or not really interested please do not waste your time in a temple. But if you are then a first visit of Bangkok should include a visit of the Wat Pho with the giant reclining Buddha (when Lord Buddha dies) and the famous massage school. Then next to it is the "Grand Palace" or "Royal Palace" with its "Temple of the Emerald Buddha". And of course the Wat Arun (temple of Dawn). Are you tired of temples? Then visit "Jim Thomson House" what is a traditional wooden Ahuthaya style house complex that turned into a museum of the private collection of Jim Thomson.
Want to see what Bangkok is also famous for? Then head out in the evening and visit Patpong. Originally 2 small streets where western companies did setup their office. But slowly it was turned into a red-light district with mainly A-Go-Go bars. And although they are still there it has changed slowly into a night bazaar / market for they many tourists that visit Bangkok. They real A-Go-Go business has moved on to area's like Sukhumvit Soi 4 and Soi 23. Although also there a changing hand can be seen. Also do not miss a show at "Calypso" at "Asian Hotel" to the the "third gender of Thailand" although I am sure many are still believing that at least some of them are really ladies.
But what is Thailand and thus also Bangkok without food? Go eat Thai food! Very simple (but noisy) are the food courts in all shopping mall. A food court has many small kitchens where different kind of food are sold. And in the middle are tables to eat. It is all setup inside and all kitchens have clean water, gas and Electra. For a romantic dinner make a dinner cruise over the Chao Phraya. The big hotels along the river have their own boat but in front of "River City Shopping Mall" are departing every evening a few boats.
What did I say? A few days Bangkok? The first time I was in Bangkok in 1985 and after 2 days I thought "this is hell" .... I lived in Bangkok for 2 years and I still love it to come there for a few days. I hope also you will fall in love with Bangkok.