NUKEPROOF'S CARTRIDGE BEARING bottom bracket fits all standard 68mm and 73mm shell frames (there's an 83mm version too) and can be installed using a conventional BB tool.
It has CNC machined cups, a central alloy sleeve and comes with stainless steel bearings as standard, with a ceramic option too.
Disappointingly, the non-driveside bearing seized on us after just under four months' use. It's been an exceptionally wet winter and the BB I should last longer if you ensure there's plenty of grease around the bearings and use a water displacing lube after wet rides. But we've had other BBs outlast this one by years.
PRICE: 45$