Hayao Miyazaki is the only director that I know who has consistently put out masterpieces his entire career. Before Avatar I would have put Cameron in that same spot.
I didn’t care for Hateful Eight or Once Upon a Time in Hollywood. It’s always hard for me to decide whether Tarantino is exceptional or has the right people around him at the right time (which is also an exceptional quality). He has 4½ excellent movies (counting Kill Bill as 1) and a bunch of OK movies.
I'd put three of his as no brainers excellent (Pulp Fiction, Inglorious Basterds, and Reservoir Dogs. I'd put everything else in the good to very good category.