I've played with pretty much any film I come across, and in terms of cost-benefit I've settled on Fomapan films. I like the grain structure, they are some of the cheapest BW film available and have great latitude if you like to mess with stand development. I shot this photo on a Pentax ME camera using Fomapan 100. Developed at home with Ilfotec DDX and scanned with a Canon 5D Mk3 + Canon 100mm f2.8.
I've been using a bunch of Kodak 5222 ("Double-X"). I got a bulk roll of it a few years ago, like 130ft for $20. Slightly expired but still pushes great to 400 or shot normally around 200.
Higher sensitivity and I'll go for HP5, but that is getting less common for me nowadays.