Really enjoyed this one from the film trivia archive:
[ba-quote]There are 399 questions asked in the film, including “tag questions” (i.e. – “Subconscious is motivated by emotion, right?”). Cobb leads all characters with 113, followed by Ariadne (93), then Arthur (44). [/ba-quote]
I was obviously aware that there were a lot of questions when I was watching Inception but that is a crazy amount!