Maybe I'm weird, but I loathe body text in sans-serif fonts. They aren't all equally bad, but ilI are often confusing. Just the other day I was reading something somewhere with a name that ended in "ill" and I had to copy-paste somewhere else to tell it wasn't just a roman-numeral 3 smushed on the end.

And of course sentences that start with "Ill" just break my flow of reading.