Does anyone know what the least awarded badge is?
How many times it has been awarded?
Edit and answer 500 questions (both actions within 12 hours, answer score > 0).
Three badges have never been awarded (Tenacious, Unsung Hero and Stellar Question). As regards the first two, while it may be mathematically possible to get them, on a site with traffic this high it's deeply unlikely that anyone will actually get them.
The third one (Stellar) is closest to being achieved by In what order should the Star Wars movies be watched? & What order should Asimov's Foundation series be read in?.
If you want to see the current badge counts, they're here