iZotope Vinyl allows you to create a "lo-fi" sound using vinyl record and phonograph models. Although it's free, we set a goal of professional quality, both in look and feel, as well as sound quality. Of course, in this case sound quality means making it sound realistically bad, and we spent significant time tuning models and samples and developing 64-bit signal processing for noise shaping, distortion, EQ, and dithering.
Check out the Overview and Quick Start - 10 Steps to Lo-Fi to learn how to make it so bad that it's good. Or click on any of the links on the left to read more about that topic.