I have tried to think this through and I'm really struggling to answer this question, I have so many favorites. Too many bands also but that's another story
For context, I own Sport Loops, Sport bands, Leather Loop and some leather bands from FFF. Catch me on any given day it could be any one of them, I change bands in cycles.
Practicality vs. favorite is difficult enough a choice for me to name one band as the winner. Then we get into the different materials and colors. For anything that involves physical activity, I prefer sport bands, hands down, no questions asked. For business casual or more upscale casual scenarios I favor one of the leather bands. General day to day, I seem to be wearing a lot of sport loops these days.
As comfortable as the Sport Loops are, I really think the leather from FFF is still the most comfortable I own, likely one of the most practical as well.
Long story short, I still don't have an answer