Of the Tarantino works I've seen, I'd probably rate them as: Pulp Fiction, Jackie Brown, Reservoir Dogs, Hateful Eight, Inglorious Basterds, Deathproof, Once Upon a Time in Hollywood, Django Unchained. But even thought I'd put Once Upon a Time near the bottom, I still thoroughly enjoyed it. It's not like the Cohen Brothers where I love some of their stuff and then hate some of their other stuff... I dig pretty much everything Quentin Tarantino has done (that I've seen).
I know there are some other movies he's been involved with (Dusk til Dawn, Natural Born Killers, True Romance, etc.), but I'm not counting those, because they're not part of his "10" (or at least I don't believe they are). I actually haven't seen True Romance, but it sounds like I should. I also have to check out the Kill Bill movies, which I've steered away from after hearing they were pretty gory... not that some of the others on that list weren't, I guess. But I don't think QT is overrated as a director. He has his quirky tendencies, and I guess you could like them or dislike them. But I still think they're mostly done with a pretty high quality.