"As a general rule, strategic 1v1 games are only long when both players are bad and fail to capitalize on an early lead."
When we are looking on "longest game" we are obviously not concerned about the general game.
Also, all the longest game could in many cases be prolonged, by playing until elimination or simply not eliminating at all.
Not to mention that the map is important, some map are simply bigger.
That being said, I like this thread. Therefore I am contributing some games to the list :)https://www.warlight.net/MultiPlayer?GameID=6675859
(33 turns, best in terms of skill)https://www.warlight.net/MultiPlayer?GameID=5342038
(35 turns, I concurred the whole map xD)
P.S I used past games, then searched for "You won in 3" turns.