There's a decided charm about this British film. The devilish glee with which Maggie Smith does away with her adversaries is delightful, and the plot twists are fun to see unfold.
This film was released recently enough to have a DVD release built into the marketing plan. It's more of a future obscurity factor candidate because it's still somewhat fresh in people's memory, but this blog is as much for posterity as it is for now, so I decided to include it. The trailer above is uploaded to YouTube by YarcoTV.
Obscurity factor: 4 (recently released, on DVD, doesn't have a high profile)