Anyone has suggestions on good papers in English translation from the archive? Here's one that is the first published proof of Fermat’s Little Theorem (link to translation at bottom of page):
Euler's first major work, the one that brought him fame, was his solution to the Basel problem (https://en.wikipedia.org/wiki/Basel_problem), when he was 28. Namely, he found the sum of the reciprocals of the squares of the integer, i.e. the value of the series (1 + 1/4 + 1/9 + 1/16 + ...), to be π²/6.
http://eulerarchive.maa.org//pages/E054.html