I visited Pattaya with my wife and three kids as a short "stop over" as part of a vacation to Siem Reap in Cambodia. We'd been to Bangkok before, so we thought we'd try a different city in Thailand that was drivable, and with a beach. Big mistake....
If you are a 40+ guy with a bottle of Viagra and desire for 15-year-old girls, by all means this is a great place. But for anyone else, it is a complete dump, with a dirty beach as well.
I have been to many corners of Thailand, and it is a wonderful country! Even with my wife and three kids (6, 8, 10), I have never been put off by the sex tourism you see in Phuket, Chiang Mai, Bangkok, etc. However, you can avoid it and steer away from it if you have kids in those places. In Pattaya, it is in your face non-stop.
We ate at an international restaurant one night (in same building as Ripley's...can't remember its name) and we saw a Russian woman, maybe 24, who was clearly drugged, eating with a giant Russian muscleman and a much older woman. She looked like she was there against her will, and was probably being trafficked. My kids noticed her as well ..... that is not the kind of thing one wants to try and explain to your children.
After a horrible walk where we discovered what the true character of Pattaya is, we spent our four days within the confines of our hotel (Marriott .... nice pool).
Visit Thailand? YES!
Visit Pattaya? NO!!!!!!