Heh, I'm afraid I'm going to show my age right off. It was Merry Christmas Mr. Lawrence.
What is your favourite Kitano film that you've seen so far?
Film in general? Merry Christmas Mr. Lawrence. As far as his contribution to a film, Battle Royale. But as I said in my review of BR, "I suspect you could put Takeshi Kitano in an elephant suit and have him quoting random passages from Valley of the Dolls and he'd still add to the overall quality of a movie".
Do you prefer him as actor, director or comedian?
My experience with him so far is only as an actor, though Dolls is something like third or fourth on my Netflix queue. I would like to see more of him as an actor, actually.
What Kitano films do you own? (where he acts or directs)
Currently, none, since I believe my old taped-off-of-cable tape of Mr. Lawrence is unwatchably old. I expect I'll get around to purchasing Battle Royale eventually.
What is your opinion of Takeshi's Castle?
Never seen it, but from the description it doesn't sound like something I'd enjoy.
So anyway, I'm certainly not the fan that some are, but I expect to be more of a fan as I see more of his work.