I have used Dewalt, Milwaukee, Ace brand, B&D, Lenox .....I never ever buy anything other than Lenox. How many of the others can you bend in a L shape...multiple times...bend it back and keep on cutting.
I would rate them in this order: Lenox Milwaukee Dewalt/Ace B&D
I've had good luck DeWalt blades for metal cutting, also Lenox work well. I've never had any good luck with store brand cheap junk. I've found that the more expensive ones are generally cheaper to use when it comes to reciprocator/sawzall and jigsaw blades.