John , my favorite is the Subsite , a division of Charles Machine Works a.k.a. Ditch Witch . However , Vermeer pushes a Mark IV SpotDetek . I believe they have a brand new model , called the Eclipse or some similar name . You can find both of these on the previous companies websites , and used ones are selling on EBay. If you want the absolute best , and be prepared to get a bank loan , Radiodetection makes the one the AT&T Fiber Locators use . I haven't seen anything that one can't do . Only thing missing is GPR ( ground penetrating radar )
I was curious , are you locating for a HDD rig , or , just trying to locate utilities ?