From Porniki The Porn Wiki
Taboo Stories is one of the oldest erotic stories membership sites on the net. Erotic stories have been a staple of the computer world for as long as their have been modems, networks, and a way to pass the information. Magazines such as Penthouse Letters and others have covered the subject for many, many years.
Interestingly, while there has been a huge growth in the demand for video and images, written word erotica and sex stories have remained strongly in demand, and actually appear to be getting more and more popular.
Taboo Stories has about 20,000 or so erotic stories inside the site, plus some other nice features. The stories cover all subjects, their tagline being "nothing is left out, nothing is taboo". You will pretty much find everything from virgin sex, to slut wives and gangbangs.