The type of surface that the scraper blade will come into contact with also affects the life of the blade. Rougher concrete tends to dull blades much quicker than a smooth, trowelled surface.

OXO Good Grips Stainless Steel Scraper & Chopper This one is my favorite. The design is flawless. It has a wide stainless steel surface, a sharp edge, and a nonslip handle for stability.