Gawd! There are so many that I can't do without, from my 1/2" impact to my plasma cutter to my mig welder to my cut-off tool. But I suppose if I have to pick just one it would be my floor jack. It lifts higher than any other I have found, it is bulletproof, and built right. This is the 2nd one of this brand (Ausco) that I have had. The first one only lasted for 25+ years under heavy commercial shop use, by every careless person in the shop. This one is almost as old and just as abused, but I bought it used from my Snap-on man who took it on trade. Sure wish I could find another one