28 Days Later

One of the best zombie movies ever made with many of the genre's "firsts:" 1. The first that begins with an actual explanation of what created the zombie plague. 2. The first to introduce a fast-moving "infected" horde, ratching up the tension significantly. 3. The first to infect people instantly (within seconds). It also has one of the best movie scores, one that rivals those from John Carpenter classics "Halloween" and "The Thing." It is striking how the music can elevate a movie or a scene. The biggest issue, which to be fair, is not something Danny Boyle and his crew could have foreseen, is that it was shot in low quality SD, making it nearly unwatchable on large screen modern HD or 4K TV's.