White Zombie, considered the first zombie film, was released in 1932 and starred Bela Lugosi as a Voodoo master in Haiti. I'm surprised this one isn't generally better known.
You can watch it via youtube:
1000 Misspent Hours says, "White Zombie was, to the best of my knowledge, the very first voodoo movie, and some 70 years later, it remains one of the best" and calls it "beautifully composed, technically groundbreaking, and blessed with what is probably the second-best performance of Bela Lugosi’s mostly unimpressive career." It get a 79% score at Rotten Tomatoes.
9/14/2009: 366 Weird Movies says, "White Zombie can send quite the uncanny chill down your spine at times and is well worth a look for those seeking to soak up some classic Gothic atmosphere"
9/29/2012: The Husband has never seen this one so he's choosing it to watch tonight.