Pattaya

Resort town with a population of over 100,000 about 165km southeast of Bangkok. Infamous for its nightlife and go-go bars efforts have been put into becoming family destination as well.

Wikitravel says:

Pattaya is a popular resort on the North Gulf Coast of Eastern Thailand, 150 km south-east of Bangkok. In the Western conception Pattaya is most famous for its go-go and beer bars but besides the men and women on offer, the place has recently upgraded itself to be one of the best family locations in Thailand. Even though Pattaya hasn’t completely lost its ‘seedy’ side, it now attracts a huge amount of local Thai, North Asian and South Asian tourists who are just there with their families for a fun time. The local authorities-in-charge have, over the past few years, certainly improved the quality of the beaches but some of them are still lackluster (by Thailand’s high standards) and rampant over-development has long since destroyed some of the natural charms it once had, but its plethora of hotels and guest houses and convenient location with quick and easy access from the capital make it a popular weekend getaway. Catering for over 5 million tourists yearly, Pattaya is also able to offer an excellent range of eating choices and a wide variety of things to do and see. and its population is a colorful potpourri of mixed nationalities from near and far.

Wikipedia says:
Pattaya (Thai: พัทยา) was a small fishing village until it was discovered by Bangkok residents in the 1960s. Soon thereafter, servicemen from all over Southeast Asia, including the United States Air Force base at U-Tapao in neighbouring Rayong province began using the area for "rest and recreation" (R&R), causing a huge boom in prostitution. When the Americans left following the end of the Vietnam War, the city fell into a crisis. The rapid growth of tourism brought about many negative consequences, such as pollution and petty crime. In 1976, the Pattaya City Act was passed by the Thai legislature, making Pattaya a self-administrating municipality governed by a Council-manager government. However, many argue that this administration system has drawbacks (for example, the mayor may disagree with the city manager). Critics have recommended abolishing the system. In recent years the city has pushed hard to clean up its image, however the core sex-industry has ensured that Pattaya retains its position as one of the world's most visited party destinations. Despite these efforts, Pattaya's sex industry is the city's raison d'être. ... read more