Check out the 2018+ Fat Bob owners page on Faceborg there are a lot of guys using different exhaust, mostly 2-1. Even some sound clips.
Cheers!

 

Lot of options. In the end it'll come down to what you are looking for and what suits you best. Want something loud? 2 to 1? Slip ons? Personally I love the color of the stock heat shields with the black slip ons but I wanted the most I could get out of the stage 4 upgrade so I went with at 2 to 1, the D&D Bobcat upswept with carbon sleeve. It sounds great, on the loud side but I love it. I wish there was a heat shield for the 2 to 1 that was the same color as the stock pipe but ah well. The color and setup of the stock, to me, is what stands out about the fat bob.

 

 

D&D Exhaust has 3 different versions in both chrome and black for the bike. I am partial to the Bobcat.

 

 

The lines on that look similar to the stock exhaust. If the stock heat shields could be adapted to fit that V&H pipe, and I could get the pipe in black, that would be a pretty compelling option.

 

 

I went for the Bassani Road Rage 3 (stainless) in the end. It's a well built pipe, sounds good (loud, but not tinny) and performs very well.

110HP and 126TQ on the Dyno with HD's Stage 2 Torque cam. More than 110TQ on tap all the way from 2400 to 5500 RPM. Max torque at 3600 RPM. Just how I like it!