I enjoyed Harris's portrayal much more. He always seemed wiser than Gambon to me. He had the knowing twinkle in his eye, and he always seemed in control. When he walked into the room, he had an aura about him. Gambon seemed too angry, not as eccentric.
Gambon...Maybe I'm not giving him enough of a chance, because to me, Harris was Dumbledore. Once someone has begun a role, I think it's near impossible for anyone to replace them.
I think that they both bring different things to the table, good and bad.
But Harris is now and always will be my Dumbledore. He is what I think of when I picture Dumbledore. He is kind, calm, old but still chipper, and let's face it, he just looked like Dumbledore.
Definitely Richard Harris. He just does a better job at portraying Dumbledore, not to mention he looks more like him in my opinion. Gambon is always so serious and mean, he doesn't have the lighter, odder side of Dumbledore. I could never see him saying "nitwit," "oddment," "blubber," or "tweak." You know the name Dumbledore means bumblebee, because Jo could picture him wandering around the castle humming to himself? Gambon couldn't pull that off. And he's so short lol. Btw, if you haven't heard Harris's "MacArthur Park" you should listen to it. When I was little my dad would always play it but the only lyrics I heard were, "Someone left the cake out in the rain, I don't think that I can take it, 'cause it took so long to bake it, And I'll never have that recipe again," in this really dramatic way so I sort of dismissed it as my dad's ridiculous music lol.