Monsters and Madmen is an unusual but welcome addition to the collection. It is a solid representation of a very specific kind of film from a very specific era in film history. While many of the movies from this era have become extremely campy with passing time, even the rudimentary effects of The Atomic Submarine and the ridiculous costume in First Man into Space are easy to ignore because you are invested in the story and more amazed by the filmmakers' sheer (perhaps misguided) confidence to pull it off.
Of the four films, I enjoyed Bennet's more than Day's three. Not only did The Atomic Submarine have the most enjoyable effects, the best lines, and some of the more interesting philosophical underpinnings, it was also for me the most fun by far. I loved the alien, whose look recalled The Simpsons and intentions recalled The Twilight Zone. I loved the ship, one of the most obvious models I've ever seen in a film, the kind of effect that makes you think Ed Wood wasn't so off the mark. Mostly, though, I loved the score, which was futurism at its wackiest.
Then there's The Haunted Strangler, which I actually think could be remade with a few tweaks to make the reveal a bit more believable. In fact, Karloff's performances in that film and Corridors of Blood helped carry the movies. The only one I didn't really like First Man into Space, most likely because the threat seems so unlikely to us now (the film was dated in just a few years). Still, a great collection, and while it's not the ideal set for me, it's the kind of thing that probably changed the lives of a few fellow nerds out there.
Links to individual reviews:
First Man into Space
The Atomic Submarine
The Haunted Strangler
Corridors of Blood