Well, what can I say? YOUNG FRANKENSTEIN was my #1 pick. Anyone who knows me could have guessed that.
I think YOUNG FRANKENSTEIN is the most even, well done of Mel Brooks's movies, and I credit a lot of that to Gene Wilder, who wrote the original script from his concept of the parody. I'm sure the silly bits are Mel's contributions.
They used the original FRANKENSTEIN sets for this movie, adding to the allure of its parody/homage status. And, I think the casting is perfection. And snagging Gene Hackman as the blind man was a stroke of genius, IMHO.
Naturally, I saw this one in the theater when it was new. I was 14. I was already enamored of Mr. Wilder (from BLAZING SADDLES the year before), so I wanted to see it as soon as humanly possible. My mom worked nights then, though (she would have been the most likely candidate to take me, since it was showing in a theater a few towns over from ours), so I thought I'd have to wait an interminably long time to see it. (The outrageous fortune of being too young to drive!) But somehow I talked my dad into taking me to see it. I don't remember a thing about my dad sitting next to me. I just remember sitting there in the theater (it was a weeknight and a school night and not crowded at all in this small town), feeling completely alone and in heaven, eating popcorn and melding with the movie. It was glorious.
Oh, I was the only person in the theater who laughed in the beginning (before very much funny has happened yet) when an eerie grandfather clock is striking the hour. Apparently no one else thought to count those strokes -- of course there were 13, not 12.
Shortly after that, I bought the soundtrack (on vinyl), the movie poster (which graced the main wall of my bedroom till I went to college), and the T-shirt. Somewhere the T-shirt and poster disappeared into the universe, but I still have the vinyl soundtrack. I think I wore down the grooves in "Puttin' on the Ritz."
Since that time, I've seen this movie well over 100 more times, and for a LONG, LONG time, I discovered a new joke or reference that I hadn't noticed before. I'm pretty sure by now I've exhausted all the jokes and references, but I still can watch it and feel like it's the first time, hoping something new will make me laugh afresh.
I agree with Holden that, if you're going to watch this movie for the first time, watch the two originals to which it's paying homage first. Although, even if you do it my way (watching those originals many years later), you'll get a kick out of it. You'll just be laughing at the original horror movies instead... which I admit is kinda weird.