Ninja Assassin!
This movie is a 100 lb box of awesome! There are a few minutes of unnecessary talkiness, there's more CG blood than I care for, and I think that ninjas are not really hiding properly when they engage in street battles in the middle of traffic, but other than that I think this movie delivers about everything one might reasonably expect in a movie about ninjas: frenetic combat, over the top violence, and stealthy assassins who blend into the shadows of the night. The plot is spare, but straightforward, because you really aren't coming to see this movie because of the plot. The characters, other than the central character are not developed to speak of, but you aren't coming to see this movie because of the character development. You're coming to see a lot of badass ninja action, and Ninja Assassin delivers in spades for almost all of its 99 minute runtime.