And yes, I recognize that a dollar menu burger is not exactly a fair evaluation of burgers in general, but I'm mainly looking for "cheap but decent enough I would eat it again". And since I don't much care for most standard hamburger condiments, I got 'em plain.
BK Bacon Burger - Pretty bland. The bacon has almost no flavor at all, and the burger itself really only tastes like grilling char. Inoffensive and edible, but not really worth a repeat. I'll try their cheeseburger next time I eat at BK.
McDonald's Cheeseburger - The cheese is nice and zingy, and if the burger is also bland it at least offers no offensive counter-taste to clash with the cheese. I'll probably have these again, if not as often as McChickens.