Mine might be a tie. I guess this says something about me as both of these tools are FAR from precision instruments. Notice I don't have dial calipers or feeler gauges as my favorite...I'm just an unrefined brute.

My angle grinder. It's seen a ridiculous amount of hard use in the past 3 years and wasn't very expensive to begin with...$30 maybe. Hasn't skipped a beat. None of my 4 Hitachi tools have failed me, for that matter.


The second is my ball joint pickle fork which I've used maybe 2 or 3 times to separate ball joints. But I've used it hundreds of times for other random tasks.

 

My OBD scanner. Has saved me literally thousands of dollars being able to identify problems and fix them myself.

 

My 2 post lift is by far the only tool that matters....without it I wouldn't be in the car hobby.

 

That's a very valuable tool for my Subaru.

Wish I had one of them! Or even just a garage to work in. At least I have a garage to put my tools in, but it's only barely big enough to squeeze a tiny car into let alone my truck with space to work.

 

Hmm.. Hard to choose

3/8 IR air ratchet
GearWrench XXL indexing ratchet wrenches (these things are seriously really long, and very nice)

Obd2 scanner - saved me from burning down my truck once. (Seriously)

Long story short, got my Dakota, 75 miles later the transmission started to screw up really bad. I said "I aware to god, if you're going to live up to the ****ty *** dodge name I'll take you back to the dealer and burn your *** down on their front door"

Speed sensor. Been great for 35k miles.

 

If we're going to count shop equipment as tools, then I agree. My (4-post) lift is the best thing I ever bought. But my welder comes pretty close.

 

Yeah welder is pretty important to me as well...really opened up possibilities and it's one of my few tools that actually requires real skill to use, so it's like learning a craft every time I use it.