Which part is your favorite and why? I personally like part 2 because of all the cool futuristic props in the movie like the hover board which played a major role in every year marty went to.
2nd is good, but the first one is simply epic. I was a kid when I first watched it, and I did not blink for hour and half. It's a trilogy meant to be that way from the beginning, so all the parts are well integrated in the story. I vote for the first one, it was more realistic (for me as a kid) well integrated in the present but with that cool Dolorean flying at the end, Marty and Doc were the most charismatic, too. Travel to the past and alter the events in present, that is more my type of story. Never the less, great trilogy, recently I watched all three parts together.
i'm really a fan of all three, as even though the basis for the storyline for the 1st and third are the same, each one brings something a little different to the table. i'd have to say the first one would be my favorite, mostly because i think someone who has to go back will have a harder time adapting than someone who would go forward.