I don't know about the other posters, but I would appreciate it if next time you start a thread you just say explicitly that you only want USA bits instead of saying you prefer USA made. "Prefer' implies an open mind along with a lean towards one particular side when all else is equal, not that it has to be one way and anything contrary is dismissed and talked down to. Doing that would have saved many of us the hassle of responding to your thread. Just because some of the recommendations weren't US made doesn't mean it was because we didn't have the intelligence to read your OP properly. I did read your OP and I brought up the HF bits purposefully because your OP was heavily biased against HF bits even though you have never used one yourself, and one single past use of a unibit does not usually mean that you now truly need the slight extra capabilities of a $20+ US made higher end bit. A $3 step bit in the hands of someone that knows what they are doing, along with a few drops of cutting fluid will most likely last longer than a high quality bit run dry in the hands of someone with lots of opinions and little experience using it. Having more bits vs one good bit at the beginning allows you to learn their use and make mistakes without it costing you so much. Please try to embrace the gray a little bit more, not everything is so black and white. There are actually a few great value items at HF, and the US does actually dramatically overprice things and/or produce junk sometimes. Sometimes price differentials are worth it, sometimes they are not.
Anyways, those Drill Hog bits do seem pretty nice for the price. I might try one out myself some day. Thanks goes out to lilcraigford for mentioning them. The company does seem a little seedy in how they market their stuff as being USA though. I almost feel like they are Neiko USA all over again, but there are a few places online where it is mentioned that the bits are made here, so hopefully there is no deception going on.
Last but not least, Irwin unibits work fine, but they do dull a little faster than some of the other popular US brands and if you are someone with DIY sharpening ability some of their offerings are harder to sharpen because they give the cutting edge a curved shape from top to bottom. Most other brands use a straight cut that you can sharpen easily by just running a fine grinding wheel (angle grinder etc.) along the flat cutting edge from top to bottom. You have to be a little more careful and/or creative for a satisfactory result sharpening curved Irwin unibits.