Do I need to buy The Fifth Element again?

[N-OS X-tasy!]

Yes, be sure to get the remastered BD, not the original. The white sticker along the top of the case actually says "The Fifth Element (Remastered)", so it's easy to tell.

The remastered BD is stunning. Ditch your DVD copy ASAP and get the BD - this film DEMANDS to be viewed in hi-def.