When Fitzcarraldo tells off the local magnates who are, to say the least, skeptical of his plan: "I will outmillion you. I will OUTBILLION you!" and then stalks out, followed by his mistress (madam of the local bordello) and all her girls, noses haughtily held high in the air.
Most definitely the last few minutes of the movies, when after Fitzcarraldo's plan has gone down in spectacular flames, he's sitting disconsolate on the dock when he hears that the opera company he's been trying to attract to Iquitos is looking for a gig. Cue truly splendid endpiece, with said opera company floating down the Amazon into town on rafts, Fitzcarraldo in the lead with a cigar jauntily jutting out of his mouth. Also qualifies as a Crowning Moment of Heartwarming.