It's been a while, and he references dozens of movies, so much so that you're watching his movies and think "wait, I've seen this before" and then you're distracted by the next scene you've seen before. But off the top of my head Vanishing Point, Foxy Brown, Lady Snowblood, Bruce Lee movies, and the Dirty Dozen.
But don't watch those. I probably enjoyed Vanishing Point the most, Bruce Lee in Game of Death is also fun, but often they have a few good scenes, the ones that Tarantino copied (sometimes poorly), but the rest of the movie can be a bit meh. Instead watch Oldboy, Lady Vengeance, In the Mood for Love, Infernal Affairs, Unforgiven, and (why not) Enter the Void. Not that those are my favourite movies, but they're movies that shouldn't bore you.