#RPGaDAY Day 1, First RPG Played
That one is pretty easy. It was an odd ball combination of Holmes Basic with the AD&D Monster Manual back in 1979.
It was typical of the time with 1st level characters with enough magic to take on Dragons. It was crazy, broken and we didn't care. We had a blast. It was not till the Moldvay set came out that I really started paying attention to the rules.