Which film has the best dance of the Tango? And to be fair, there must be a video of the dance to each film entry so you can judge them properly.
And if the Tango has you tangled up, untie yourself here. (Yes, that line contained a play on words reference from one of the lines in the movies listed here.) if you want to suggest one, you have to give a link to the dance in that movie in order to be considered.
(WARNING: IMHO, the two Rudolph Valentino ones are going to be hard to beat. That Tango in The Four Horsemen of the Apocalypse (1921) still holds up today.)