Underappreciated directors on here that you'd recommend?

I guess it depends on what you define as "underappreciated", but here's my own take.

Jerry Schatzberg - Started out as a photographer, and went on to make some of the most intriguing films of The New Hollywood Movement like Scarecrow, and The Panic in Needle Park (both with Pacino). Unfortunately he doesn't seem to be talked about as much compared to his other Brethren, and that might be partially due to his own doing. The second half of his career is a wee rough.

Carroll Ballard - One of the great directors of nature. He would have been perfect for a 1970s version of The Jungle Book. He's only made six movies, but they're almost all worth looking into. Never Cry Wolf is terrific, while Fly Away Home and The Black Stallion are sentimental favorites for me.

Don Coscarelli - Only made ten films, but almost all of them I can recommend. Probably best known for his genre "cult work", his career consists of gems like The Beastmaster, Bubba-Ho-Tep, and The Phantasm Franchise.

Larry Cohen - Both famed as a writer and director. Similar to Coscarelli, he also dabbled in a lot of genre flicks, particularly of the horror variety, but his filmography is much more varied then that. You've got blacksplotation films like his debut Bone, bizarre horror flicks like The It Lives trilogy, and then there's much more fun, more explicit gross comedic affairs like Q. The Winged Serpent, and The Stuff.

Ralph Bakshi - Although I've talked about him on this board, I don't think his actual work is appreciated enough, especially as of the few true auteur animation directors of The New Hollywood era. Bakshi's rotoscopping style is not for everyone, but once you get past that, you've got a lot of variety, and I find his career endlessly fascinating. Social commentary character pieces like Heavy Traffic, and Coonskin, acid trips like Wizards, and big fantasy epics such as his Lord of The Rings film, and Fire & Ice.

When the term 'underappreciated directors' comes up, I instantly think of Frank Perry. His collaborations with Eleanor Perry are really fascinating and absolutely worth examining and experiencing. I wish Criterion put out a boxset with their joint projects - they beg to be restored. The dialogue about him often gets overshadowed by "Mommie Dearest" (which isn't even THAT bad) but his 60s films are terrific.

Great pick.  Housewife, Last Summer, The Swimmer, Ladybug Ladybug - all very good to great to better, stinging dissections of American ideals and self-denial and distracted, disturbed games too.   That'd make a helluva boxset.  Ladybug holds up now powerfully with its do-we-panic despair and how empty spaces can become horrifying... 

Another director I'd definitely recommend is Mohsen Makhmalbaf who is probably as important to Iranian new wave as Abbas Kiarostami. His films Salaam Cinema and A Moment Of Innocence are masterworks of combining fiction and nonfiction. He has also made a couple of great impressionist works like Gabbeh and The Silence, which are equally fascinating.

this thread has really nice choices so far

jon jost whose takes on americana and blue collar woes are some of the most emotionally trying ones out there, a maverick that i always admire. i hope i get to produce his next flick

jem cohen i have only seen a couple things from but his work is quiet and can be either warm as in Museum Hours or dreary as in Chain, definitely someone i wanna see more from

people know who ida lupino is but i genuinely see her as among the best classic directors of her era, just unending empathy on the screen

adam curtis is a fantastic storyteller through documentary and knows more about montage than just about anyone living today, i only watch him with my gf but we gotta delve into his filmo more

tobe hooper is a name everyone knows but the man seriously has like 10 good movies under his belt and was not a one hit wonder at all, crazy how he could use camp like few others

sharon lockhart is someone i like throwing on sometimes when i need a movie where nothing happens and i can just watch bodied in motion, she is great for that

not really a huge fan of any of his works but albert serra is worth mentioning to because he has a great sense of humor and his shit is all very different from each other

finally TAKASHI MAKINO please people he is the best to ever do experimental cinema there is nobody at his level

Great pick.   The Hitchhiker and The Bigamist are really solid, and The Trouble with Angels is marvelous. Also a ton of TV work to root thru - the only female to dabble around Twilight Zone, Hitchcock Presents, and Karloff's Thriller.

Nicolas Winding Refn's Pusher trilogy comes to mind.

Not sure how much love Jonathan Demme gets outside of Silence of The Lambs