Part of a Vengeance Trilogy of which the more well-renowned Oldboy belongs to. IMO, of the trio, I find that Sympathy For Lady V to more strongly emphasize director Park Chan-wook's "poetic" use of visuals (a phrase you'll probably be able to understand better once you watch it) with a story that flows much smoother into it's gritty climax that, for my money, is richly laden with an equal balance of above-the-law justice & a plausible & sensible empathy for it's unique plot-device.
So while I also recommend Oldboy as a great flick that is armed with a more in-your-face type of plot twist, I still find that my sympathies tend to lean stronger towards Lady Vengeance.
8.5/10