gandalf, the hobbit an unexpected journey, the hobbit the desolation of smaug, the hobbit the battle of five armies and the lord of the rings the fellowship of the rings. in the others he isn't gandalf the grey anymore
The Lord of the Rings. Gandalf the Wizard VS the Balrog. In the end, they both die at each other's hands, but the Balrog going first, and Gandalf falling off the cliffs of Khazad-Dum to a bottomless abyss.