It’s no surprise that Korean director Chan-wook Park’s 2003 masterpiece Oldboy took home the Grand Prix from Cannes in 2004. What is somewhat surprising is just how well it has held up in the intervening decade and a half. For an unflinchingly brutal film rife with excessive violence, Oldboy has been an incredibly influential film and one with a remarkable legacy — at least if we ignore Spike Lee’s regrettable 2013 remake. Part neo-noir, part torture-porn antecedent, all jaw-droppingly original, the second film in the director’s “Vengeance Trilogy” was the first to make his name widely known to an American audience — and what an introduction it was. You’ll never look at a hammer the same way again, that’s a guarantee.