I don't usually shoot B&W (usually color slide film), but when I do it's usually whatever true/non-chromogenic film is on sale at my FLCS (friendly local camera store). Most often that winds up Ilford HP5+ ISO 400.
UPDATE: My FLCS stopped carrying Ilford! Apparently I was the only one coming in to buy it. The only thing they carry in true black-and-white now is Kodak Tmax so I picked up three rolls of the 100 speed. The first roll of it I shot was also the first roll I put through my Konica C35 Automatic (how long have I had that camera now, Joe?... anyway, thanks again, what a fun camera to shoot with) so it's a double test of sorts. I should get the film back this weekend, I'll try to see if I can squeeze out a couple of decent scans rom my Epson.