,.:;!? 1234567890 {}[]()@#$%^&*-=_+\/<> Common issues: lLiI1oO0
(maybe throw in some ligature related stuff for those who enjoy those in their fonts)I made a super basic site like that for some fonts that I enjoy, but never really put that many in there: https://fonts.kronis.dev/
Surprisingly Ubuntu Mono is also pretty good in most respects, maybe I should add it, currently it's a split for either Liberation Mono/Cousine or PT Mono for my programming font of choice, here's a nice font chooser, tournament style: https://www.codingfont.com/ or just a look at bunch of fonts https://www.programmingfonts.org/
Not to detract from the article itself, I just stare a lot at fonts while doing programming.