Darn. I was hoping this thread was going to be about what BRAND of driver bits are best.
I was going to recommend Wera. They're made in Germany and the company specializes in screw drivers, allen keys, driver bits and related products. They certainly make the best screw drivers around.
I've bought Wera driver bits for years, and they last forever. They're the only company I know of that makes STAINLESS STEEL screw drivers and driver bits.
You don't need to know the rest...
By the way, "square drive" is pronounced "Robertson", after the CANADIAN that invented it. The only reason Robertson isn't as common in the US as it is in Canada is because Robertson wouldn't let the Ford company manufacture the screws under licence. Robertson wanted to make them and sell them to Ford instead. Ford wanted to make them so that he'd have control over the supply and quality of the screws he got. The two could never reach an agreement, and so Ford went with the Phillips screw instead. The Robertson screw is a superior screw drive, and arguably second only to the Torx drive in terms of torque carrying capacity, but it never caught on in the US like it did in Canada.