Whichever ones I can get. Spyderco doesn't seem to do that many in a year, and they are affordable. The Mules are an incredible bang for your buck. Most American-made (sometimes sharpened and ground, othertimes not) cutlery blanks are around $20 for basic ones, all the way up to close to $100 for others. A Mule, in the latest of steels, and a pretty practical pattern is usually around $50, sometimes more, sometimes less depending on the steel. It's a full-size knife, and factory-made sheaths and hardware are included; so if you're like me, and unsure if you can DIY the sheath and handles, it's there.