The Tube Screamer is a classic all around great sounding distortion, even though the stock circuit is not very complex, by eliminating the JFET bypass switching and utilizing true bypass you eliminate quite a few parts. Even more, you can eliminate the input and output follower stages a number of coupling caps and bias resistors. With just one op amp and less than 25 parts, you can make a tube screamer that sounds just great. In my implementation, I changed some values in the filter section to suit my taste and on the first stage I used BAT46 shottky diodes. These diodes have substantial reverse leakage- so you have to lower the impedance of the feedback pot and resistor that controls the the drive gain. That is why I used a 50k pot and 100 ohm resistor. I used the shottky because they start to clip much sooner and you can get a really insane amount of overdrive. Regular silicon diodes work just fine. The original stock values can be used and can be found on the web.
Demo (coming soon)