I built a few LaTeX templates years ago for my Org Mode exports. My default template just stopped working for some reason. I thought maybe I'd change the default font to sans-serif while I was in there. 30 minutes later, I ended up with this:
\renewcommand{\sfdefault}{phv}
\renewcommand{\familydefault}{\sfdefault}
Now, at least I get Helvetica, and that's good enough because actually choosing a specific font would take the rest of the day, probably.