George Romero had originally envisioned DAY OF THE DEAD as the jewel in his undead crown, a large-scale epic that was once described by FX guru Tom Savini as "BEN-HUR with zombies." Unfortunately, once it became clear that his concept wasn't going to meet the standards of an R rating (required to make a project of such scope profitable), Romero opted for the unrated route; it granted him the artistic freedom he desired, but it cost him dearly, budget-wise. The scaled-down final version disappointed the majority of fans when it appeared in 1985, and for many years was considered the least of the trilogy (and you could've counted me among those who felt that way). However, in the past few years the film has gotten a second chance with both critics and fans, who've come to appreciate DAY on its own considerable merits.
I think much of the initial let-down was due to the lack of zombie-action in DAY. After the wall-to-wall mayhem of DAWN, the more human-oriented DAY no doubt felt anti-climactic. I don't know how much was dictated by finances, but Romero opted to stay underground and study the interactions of his military and civilian characters (not to mention Bub, the next step in Romero's evolution of the undead, played by Howard Sherman in a remarkable performance). That focus is the cause of a drawn-out second act that I'm sure helped seal DAY's early fate, though time has benefited the strength of the cast, particularly Joseph Pilato as asshole-in-charge Rhodes and the quietly strong portrayal by Lori Cardille (daughter of Pittsburgh icon Bill "Chilly Billy" Cardille, a late-night horror host who a bit role in the original NIGHT).
And though they're kept in check for most of the film, Tom Savini's make-up effects really shine when they're finally unleashed; the zombies' climactic assault on the heroes' bunker showcases some of Savini's best work, including Pilato's memorable comeuppance, and is probably the best FX out of Romero's films (DAWN's helicopter-zombie sequence a possible exception).
It's good to see DAY finally getting the recognition it deserves, though I can't help but wonder how much LAND OF THE DEAD had to do with it. Romero's newest film, DIARY OF THE DEAD, has received some positive buzz on the festival circuit, but I can't help but feel that DAY OF THE DEAD was his last word on the subject, and that any other zombie movie he makes is just a commercially-viable vehicle to tell the other stories he's got within him.