Pattaya is the famous place for travellers. Most of all know this place better than other parts of Thailand. There are beach and night entertainment. If you want to joy with nightlife, it's good to go there.

          But Pattay is not Thailand. If you really want to see Thai culture go to Chiang-mai or countryside. You will found Thai culture in there. Or if you want to see the beautiful beaches you should go to southern Thailand. (Like you see from "The beach" movie, please just only see how much beatiful of the beach but don't believe the story.
 

          Finally, you should ask yourself what you want to see in Thailand.