The Fortin NATAS is by far the best preamp/distortion pedal I’ve tried. It’s tight, versatile and absolutely vicious.
Chugs like a jackhammer and slams the front of the amp hard. Expensive but worth it.
The Griff Tone Ripper is also killer. Based on the Friedman BEOD but all around much better.
I’ve got one I’m not using, hhm if interested.