Dawn of the Dead (1978) 
In glorious 4k and yes it really does look and sound fantastic. It's the first time I've watched the Theatrical Cut in years, and my last 2 watches were the Argento version, I'm struggling to decide which I like better now. If only a few scenes were trimmed down in the Romero version I think it'd be perfect. There is just too much fluff between The trucks blocking the doors and Savini combing his mustache...