"all the sudden" seems to be the standard form in Portland, Oregon.

I think calling people 'uneducated' and claiming that they've 'never read' because they use "the" rather than "of a" is completely ridiculous. My mother is a Language Arts professor and she says "All the sudden." my father has two master's degrees and he says "all the sudden." I'm a high school student in the top percentile and I say "all the sudden." I've also seen "all the sudden" used in the newspaper, and in dialogue in a couple of books.

These kinds of variations are an inevitable part of language, and subject to locality and generation.