I like ISO 400 films because they can be pushed a bit to reach relative sensitivity needed for hand holding at night. I've shot a bunch of them. Here's a one or two sentence comment in my own words about a number of them.
Delta 400: Kind of featureless but good tonality and okay pushing latitude. A great B&W film for taking pictures of people.
HP5+: In my experience, very fine grained film, with good contrast and it pushes well. Probably my favorite film.
Fomapan 400 Action aka Foma 400: Old school grainy stuff that can push okay. Fun to play with but is cheap for a reason.
Tri-X 400: HP5-like but I found it a touch more grainy. Pushes well, good contrast, not bad stuff.
TMax 400: A good film if you want to push, a bit flat, it's basically Kodak's Delta 400 but I don't care for the tones out of it that much.
I also develop Kodak Ultramax 400 in black and white developer. Results are a bit varied and I've really liked some shots taken with it and not so much with others. It's one of the cheapest mainstream films I can find. Negatives will come out very orange, which is normal for C-41 film, which I deal with in post-processing (I digitize my negatives with my DSLR and process like any other RAW file).
My thread where I show a whole pile of images from my developing work with the above films;
Clayton F76! - PentaxForums.com