This is a brilliant concept for a film, but so far none have taken full advantage of the premise, with the latest out, here is the ranking for this trilogy.
This was one of my favorite films of 2014, and i wasn't a huge fan of the first, but the trailer looked awesome. This had a story with characters you can connect with, had political & social commentary, and showed batshit antics from the Purge. Plus Frank Grillo played Frank Castle so fucking well.
2. Election Year
A direct follow up the Anarchy, this one uses a bit more political commentary but the story is not as strong and the Purging is not as cool. The characters are a lot of fun though and the gore is pretty heavy, a few really awesome moments.
3. The Purge
Instead of showing outside a lot, they mainly made with a home invasion film of House Lanister.
They need to make a fourth one, have it set the first year, people are timid to break laws, but just have 10 minutes of self conflict and 80 minutes of various people purging balls to the wall.