With me I guess it depend on what I am doing. I have a set of Blue Point crimping pliars that cut ANYTHING and make good, tight crimps. They were $37 off the big dream truck that shows up once a week. I later found virtually the same thing at American Electic made by Klein for $21.
I also really like my Fluke 78. It has a temp sender that I use extensively for A/C work and has proven to be accurate and handy. I got a 400 amp ac/dc inductive clamp with it that has saved a LOT of time tracking down electical problems. Being able to store high and low reading is also VERY useful for intermittent problems.
It seems like my latest favorite tools are the latest ones I get. I have a set of snap gages and another dial indicator on the way from Enco. I also bought a 2"-6" Starrett outside mic from a co-worker who is retiring.
Future purchases might include a Ingersoll-Rand 2112 3/8 drive impact. I have a battery-powered 3/8 Snap-On at work that works great for a fast screwdriver or for smaller fasteners (5/16 and below), but it just isn't powerful enough for bigger things and I hate to drag around my CP-749 half inch drive around all the time. I really like that CP-749--I think it has the top power of ANY 1/2" drive on the market.
Other favorite tools I have are ones I have made to do special jobs. I made a lifting device to handle heavy rear tractor duals when the final drives have to be removed from the tractor. I can use a come-a-long to level the wheel/axle side to side which really helps when you are trying to put everything back together. These can weigh up to 3000 pounds fully weighted and are a bear to handle sometimes.
Some tools are just what is laying around. When I assemble a hydraulic cylinder that uses leathers for piston seals, I cut open an aluminum pop can and put the can sidewalls over the leathers so they will not catch in the end of the cylinder as you reassemble the cylinder. This trick has saved a lot of rework for me.
Probably the best tool anyone can have is common sense. Use common sense in any situation, know your strengths and limitations, and be willing to listen to sound advice.
