Basterds is his masterpiece. There is not a single thing wrong with it. The tavern scene is the greatest thing he's ever done. Pulp Fiction is my favorite and closest to my heart and his most influential so that's something. There's some fat on it, though I'd like to revisit it to see if I'm wrong on that.
Jackie Brown is my third favorite and I believe his third best. It's the one not talked about as much which is a shame. Max Cherry is my favorite Tarantino character. I know he's technically a Leonard character, but the casting of Robert Forrester and that performance is all Tarantino to the point where it feels like his in this case and makes it my favorite. Archie Hicox is my second favorite Tarantino character.
Death Proof is probably my least favorite but I quite enjoy it!