Greenfield, Clevland Twist are both excellant drills. Stay away from the imports, unless you just drill plastic. You can tell a cheap drill from a quality one just by looking at them. Like Audio said, speed, lube, and pressure are what will make or break a drill. Too many people think if you use a faster rpm, it will drill faster. Just burns up the drill faster. Rule of thumb, the larger the drill, the slower the rpm's. I resharpen them by hand. Peice of cake. Tried the drill doctor. I can do better by hand.
Does Snap-On (Blue Point?) and Matco actually make their own bits, or just sell them?