Shenzhen is usually the example I hear about when special economic zones are discussed. It's a really successful SEZ in China. It used to be a simple village before it was transformed into a SEZ. Now it is said to be an important industrial center in China. Many Chinese travel there for work.
There are some other examples of successful SEZs from around the world. But it's still not very popular. Industrial parks are more common. I heard that there are more than one thousand of them in China. They are pretty similar to SEZ but smaller. It is in the control of local provincial governments not the federal government. But I think when a SEZ is created, they create industrial parks around it to support the SEZ.