Give your votes to the answers that you enjoyed the most! If you see one missing, submit it yourself!
"Did Joseph McCarthy find any actual Soviet spies?" | /u/kochevnik81
Why didn’t the Soviet Union use paratroopers during World War II? | /u/jon_beveryman
"Harness racing used to be fairly popular in the US. Why did it become overshadowed by flat racing?" | /u/PM_ME_UR_SADDLEBREDS
"Was Zoroastrianism the source for Christianity?" | /u/lcnielsen
It is a tribute to the quality of r/AskHistorians that I find myself unable to help pick a winner, because every one of these threads I read through I want to vote for.