You've certainly seen Dawn of the Dead already. But you might not have seen this version. There have been a few. To briefly recap what's been written in countless blogs already: the U.S. theatrical version is 126 minutes, identical to the one that went to home video. In the 90's more versions appeared on DVD: the 139-minute Director's Cut, an Ultimate Cut that's longer, and something called an Ultimate Final Cut that assembles all the footage Romero used in all the versions. That clocks in at 156 minutes. To add to the confusion, many of the more violent scenes were removed for distribution in multiple countries.
This is the original European cut, which Dario Argento put together for all non-English speaking European countries, as was the agreement he had with Romero when he helped finance the film. According to Wikipedia it's supposed to go for 119 minutes, but the one I'm embedding here is 105, still plenty long enough for a movie about zombies in a shopping mall. The editing is tighter all around (within the first 16 minutes we move from the newsroom to the tenement to the fuel station to the mall), and the music is all by Argento and Goblin (as opposed to Romero's edit, which uses a lot of library music). Most interestingly, Argento shot some additional footage and spliced it in.
Even if you've seen Romero's Dawn recently, this is worth watching. Especially so, actually, since it's interesting to see how editing and scoring choices can make such a different movie.