It's been more than eleven years, two months since I last saw this - I know with certainty, because it provided one of my most memorable cinematic experiences. However, that said...it isn't actually a very good movie. Besson wrote the original screenplay when he was still in high school, and it feels like it went straight from a 15-year old's jotter to the screen. The script is a complete self-indulgent mess, throwing just about everything you can imagine into the mix, stirring it up and throwing it at the screen. Taxi driver Korben Dallas (Willis) has a young woman fall into the back of his cab, and discovers that she is the key to humanity's survival from the 'Great Evil', which apparently shows up every 5,000 years to exterminate all life on Earth. Which, by my reckoning means it's been repelled more than twelve thousand times since the dinosaurs went extinct. Got to admire such persistence, if nothing else. Meanwhile, Zorg (Oldman) is out to stop her - apparently, not quite clear that the "exterminate all life" concept would include him.
Like I said: not well thought-out, in a very similar way to Babylon AD - whose director, oddly enough, plays the mugger who tries to attack Willis in his apartment - and with a similar devotion to style over substance. However, where Fifth is vastly superior, is in the performances, which rescue what has the potential to be a disaster and turn it into something watchable. All the cast are at least adequate in their roles: yes, Chris Tucker is still astonishingly irritating, yet I now sense that was at least partly the point [I just don't think Besson realized quite how much]. Willis and Jovovich have exactly the right world-weary and other-worldly approaches respectively, whole Oldman overcomes what has to be one of the crappest haircuts in cinematic history, chewing the scenery to good effect. It's movie eye-candy of the highest order, and on that basis can't be condemned out of hand - the budget is all up on the screen, and it still looks marvellous, even more than a decade after its release. However, when measured by Besson's high standards, it's definitely no Leon.