Top 10 Attraction In Thailand

1. The Grand Palace & Wat Prakeaw
Bangkok

2. Phang Nga Bay.

3. Similan Islands Phanga Province - West of Khao Lak.

4. Floating Markets
Near Bangkok.

5. Phi Phi Islands
Krabi Province.

6. Doi Suthep
Chiang Mai.

7. Railay Beach
Krabi Province.

8. Ayutthaya
North of Bangkok.

9. Wat Arun (Temple of Dawn) Bangkok.

 10. Khao Yai National Park
North of Bangkok

Reference
http://www.thailand-guide.com/attractions/top10-attractions.htm