Prolific Filmmakers:
What person has the most credits listed on their IMDb page?
What person has the most credits listed under one category (e.g., Actor, Producer, Director, Writer, etc.)?
What person has credits in the most categories?
For example, Tom Hanks has 45 Actor, 26 Producer, 7 Director, 3 Writer, 3 Miscellaneous Crew, 1 Composer (he wrote songs for "That Thing You Do"), 64 Himself (appearances on things like the Oscars), 11 Archive (Saturday Night Live compilations, etc.), and 80 Notable TV Guest Appearance listings. Thus, he has 240 total credits, 80 credits under one category, and is represented in nine different categories.
I have answers in mind for the first two (though it's possible they can be beaten).