This one is for sure in my top five movies. If the Blair Witch Project and Night of the Living Dead had a baby, REC would be it!
A newscaster goes to the local fire department to do a fun story, but ends up being stuck in a building that they are called to due to a quarantine of some kind. Noone really knows until people in the building start turning into zombies... ouch!
This is in Spanish, so there are subtitles... for some reason makes it a little creepier! Quarantine (2008) is the American version for all the folks who don't like to read while watching a movie. It's pretty much the same thing but in English.