100% night of the living dead 1968 followed by original Dawn of the dead, the atmosphere is perfect in both. Zombies were perfect as well.

Man I wish Romero made that Resident Evil Film, I think he would have made it awesome.

I thought it was called Return to Zombieland (that's what I get for watching the trailer in another language).  When did that come out?

When my text while watching ass put the phone down because I was interested enough to be willing to read the subtitles then you know it’s good. And that ending! 😭

1. Dawn of the Dead '78
2. Shaun of the Dead
3. Toss up between Zombieland and 28 days later.

Genuinely the one I can always go back and watch my HDDVD copy of....

Shaun of the Dead.

It's close to being a perfect movie imo, has romance, family, drama, comedy, zombies, vinyl and an absolute ton of "Show don't tell" going on which means you can get extra stuff each time you rewatch it.

I don't watch many zombie movies, but I certainly enjoyed a few of them.

Zombieland was pretty good, but it had no sequel until recently, and the ending felt abrupt to me.

World War Z was entertaining, but not a good movie and not a good ending.

Although not zombies, just infected mutants. I prefer I am Legend the most aside from the theatrical ending. I prefer when directors get creative with as few actors as possible.

One Cut of the Dead is what i'll recommend. it is truly something else.. and in a way original.

Nothing tops the original 28 day's movie

I've seen Night, the two Dawn and Shaun. But I'd like to quote @gamingsoul with the insanity in Re-animator; and to mention Lucio Fulci's Zombie 2 "flavour" and the radioactive variation of 'Incubo sulla città contaminata (Nightmare city) 
My favourite is 68's Night

Most of the ones on that list are really good with the exception of Zombieland. I didn't like its humor or the female characters who were quite awful to be honest.

Anyway, for me it's 28 Days Later. It's really up there, neck and neck between Dawn of the Dead (original) and Dawn (remake). It just edges them out a bit cause the characters were extremely likable, the soundtrack is damn excellent, it had some trippy scenes, some more meditative scenes as well as a masterfully intense climax.

Also, to any 28 Days Later fan: I'd heavily recommend checking out the comic continuation set between the 28 Days Later movie and the sequel, 28 Weeks Later. It's made by Boom Comics and it's truly brilliant. It captures the feel of the movie completely.