Classic/Fortepan 400. Consider this a film that maxes out with a density range suitable for N-1, good down to N-4 at least. Flat, flat, flat. Also the base is thin, edges rough, and the emulsion is very prone to scratches. I tested about 2/3 of a box of 8x10" and tossed the rest, figuring I could use the freezer space more than the film.
Some films that are kind of off-the-scale "bad" can produce interesting effects. Fomapan T200 has a kind of 1930s steely grey kind of A. L. Coburn kind of Fritz Lang look. Not what I'd want to use every day, but it's interesting for atmospheric kinds of effects.
I also have about 350 feet of 35mm Double-X movie stock that must be at least 25 years old that I keep around for effects. Very heavy base fog and grainy, but it's kind of interesting in Dektol--a very long scale film.