The first Doctor to meet the Brigadier from the Brigadier's point of view was the Second Doctor. However, the First Doctor did meet the Brigadier in "The Five Doctors".
Going just by the main television series, the First, Second, Third, Fourth, Fifth and Seventh Doctors met the Brigadier.
The Sixth Doctor met the Brigadier in "The Spectre of Lanyon Moor" (Big Finish audio story), "The Shadow in the Glass" (BBC Past Doctor Adventures novel) & "Business Unusual" (BBC Past Doctor Adventures novel) as well as in the 30th anniversary special "Dimensions in Time". The Eighth Doctor met the Brigadier in "The Dying Days" (Virgin New Adventures novel), "Wolfsbane" (BBC Past Doctor Adventures novel), "Minuet in Hell" (Big Finish audio story) & "The Shadows of Avalon" (BBC Eighth Doctor Adventures novel). The Ninth Doctor met him in "Official Secrets" (comic story). And the Tenth Doctor met the Brigadier in "The Warkeeper's Crown" (Doctor Who Magazine comic story).
In "Avatars of the Intelligence" (novel), we leant of encounters between the Brigadier and the Eleventh and Thirteenth Doctors.
In "Death in Heaven", the Twelfth Doctor met the Brigadier, who had been converted (after death) into a Cyberman.
That would mean every single numbered Doctor met the Brigadier, from the First to Thirteenth. However, the War Doctor never met him.
Additionally, the Brig also met David Warner's Third Doctor that never was in "Sympathy for the Devil" (BF Doctor Who Unbound audio story) & "Masters of War" (BF Doctor Who Unbound audio story), and "Dr. Who" (a version of the Seventh Doctor from the Land of Fiction, heavily based off TV Comic's portrayal of the First and Second Doctors) in "Head Games" (Virgin New Adventures novel).