9. [REC] 2
Of course, with the turn of a new millennium came a whole new turn of filmmaking too - with the wave of found footage truly taking hold as Paranormal Activity made shaky cam fashionable. One of the standout films of the entire fad is [REC], a Spanish movie in the style that explored a fire station on lock down as a zombie-like virus spread - but it's the follow up that remains as one of the most underrated titles of the subgenre.
Sequels often suffer from diminishing returns, and whilst [REC] 2 isn't the same level as its first movie (which is almost an impossible task in itself), it certainly is an excellent horror film overall, seeing a SWAT team and a doctor return to investigate the virus during the same time period as the original TV crew. It fleshes out the lore of the original movie fantastically, with some seriously scary moments to boot.
Somehow, it's flown largely under the radar compared to [REC] - but deserves a whole lot more love than its been given in the years since release. Just don't make the mistake of thinking 3, or 4 are any good...