I also patronize B&H. It's just so convenient (and fast!) to have film delivered to my door in two days! Having said that, I do buy some B&W film locally, but I primarily shoot color slide and there's just not that many places to get it locally, and B&H's prices are significantly lower than locally.
Of course this means I order a minimum of 5 rolls from them to spread the shipping cost out over multiple rolls (which the wife finds aggravating when I "could shoot digital" but I can't project a digital file with my present equipment).