I am such a fan of the original [Rec] 1 and 2, not such a huge fan of 3 because it deviated from the urgency established in the continuity of those first two. If you've not seen these, or you've only seen the American remake titled Quarantine, you owe it to yourself. Soooo much better.
Of course, no US release date yet. Oh, and I couldn't find one with subtitles that would properly embed so here's a link to the aintitcool article that has that.