This is the ultimate zombie film... I call this the ultimate zombie film, not because it portrays the largest horde of undead cannibalizing the world at large, but because it gets back to the roots of the zombie as a metaphor.
George Romero had more in mind when he created the cannibal zombie genre than simply wanting to show people being eaten by rotting corpses. This was never more apparent than in Dawn in the Dead, when our consumer natures are explored by comparing them to the zombies who are also consumers of a different, but similar, variety (and all played out in a mecca of consumerism - a shopping mall).
That's why zombies are scary - because they are us. They look a lot like us, but their corruption is outwardly visible. They behave a lot like us, just a bit more repugnantly. And in the end it's always humans - not zombies - that are the real monsters.
(possible spoilers ahead)
Dellamorte Dellamore takes this theme and blurs it. In the beginning everything is black and white - the zombies are the bad guys and must be destroyed. But then things get fuzzy, as sometimes the undead don't seem quite so bad, maybe just misunderstood. Eventually the line between the living and the dead is completely erased and we begin to see people for themselves - not as simply "alive" or "dead". Along the way we get to explore other themes as well, such as (obviously) mortality, love, personal identity, and maybe even the meaning of life.
Pick this film up. It is clever, funny, well-directed, with great special FX, and an excellent performance by Rupert Everett. Don't forget though, this is a horror film - it has its share of violence (not nearly as gory as many Italian films, but still pretty gruesome by American standards).