I'm in agreement about adventure, but instead of knocking it to one I've swapped it with crime for position; which would be a good place for Goodfellas. Taxi Driver could easily fall into new american cinema or the seventies categories. None of it is certain, but it isn't unlikely. I've personally never seen either of the Fellini's you've mentioned, but Italy is one of the most prominent countries making up the list, along with France, due to the number of directors I've featured in addition to the film movements; making both films possible contenders for filling slots. Horror I've shown favor simply due to the fact that it is hardly represented anywhere else on the list, and because, along with comedy, it is the most popular genre with the patrons. Animation is niche, and I'm sure we could easily think of three adult examples (remember we have a family section) worthy of consideration: Akira, Waltz with Bashir, Plague Dogs, Watership Down, Mind Game, Millenium Actress, When the Wind Blows, and The Triplets of Belleville come to mind immediately.
Anyways, I believe we're ready to start. A few things may still change in the other categories, but the director list doesn't seem to have created any controversy; beyond the easily fixed Coppola deal. Here are the first five: