I bought a set of drill bits which are nickel plated (it seems) and they have proven to be virtually indestructible! [eek] It was a cheap no name Chinese set on sale and they are color coded too. After several hundred screws the two drill bits I have been using are still like new where as the Tengtools and Bosch bits would wear out pretty fast. The house owner abused the two bits when helping out (driving at incorrect angles, using wrong drill bits etc) but still not even a mark on the bits.
I have tried Wera (Diamond series), Festool, Tengtools, Bahco, Bosch, Hitachi and no name brands but none come close to these no name bits. The box is handy too. I bought four boxes so I am set for a few years I think. I might even pop over and buy out all the boxes that are left and never worry about lacking bits again.
Sometimes quality comes cheap.