So far, I love the following:
Headband Light,
Magnetic pickup tool,
Extension bars
Universal/“wobble” joints
Thumb wheel ratchet
Stubby screwdriver
Oil suction gun
X-LONG needlenose pliers.
X-LONG screwdrivers
A long handled, swivel-headed high quality 3/8 drive ratchet…I would be lost without it…
I like everything you have except the stubby screwdriver. I have never figured out what to do with one and I’ve been destroying good and bad machinery for 44 years. I do recommend buying the 255 piece Craftsman tool set for the 189 dollars and change.
Don’t bother with any hammer lighter than 24 ounces unless you plan on smashing really light duty stuff. I bought a prybar set from Harbor Freight Tools that I really like. Buy all the grinders you want. Buy the largest blow gun set you can find with as many air line pipe fittings in it as possible. I always needed more connections when I did any good amount of work.
A 200 dollar digital camera. An 18 volt flashlight for your rechargeable batteries. Goggles and face shield for dirty work or working around the car battery. Pieces of wood to use as wheel chocks. A two and a quarter ton floor jack. Jack stands. An orangutan to help you remove brake parts.
Why a swivel head and not just a U-joint?
Can you find one here?
http://www.harborfreight.com/catalogsearch/result?q=swivel+3%2F8++ratchet
What about this as well?
Ramps
Set of combination wrenches
3’8" drive socket set with a quality rachet
Deep well 6 point sockets
Mechanic’s picks
Channel Lock Pliers (Big)
Needle nosed vice grips (small)
Soldering Gun
Dremel Tool with cutting disks
Set of Torx screwdrivers (bits)
Metric and English Allan wrenches
1/8" drive socket set with good rachet
Floor jack
Big pry bar (doubles as digging bar in back yard)
2-3 dollar test light from harbor freight
Ratcheting wrenches (a bit spendy, but sometimes worth their weight in gold)
Craftsman extra long jewelers screwdriver
Heavy duty flip lug socket with 3inch extension
Air tools till the cows come home
But the most important: box of latex gloves from harbor freight 8 bucks
A set of 1/4" drive sockets/extensions and a 1/4" air ratchet is pretty handy for most smaller jobs.
I do a lot of odd and custom things and I could not live without a Dremel tool.
Right now, since I am debating doing my own struts, I have a 1/2 inch set with a breaker bar on my wish list. Also debating whether I need an electrical impact wrench-one from harbor freight for $49. Do not have room for compressor, nor the money.
@galant the big electric impact gun is good for tires, and a smaller one us good for most everything else. It’s 90% of what the guys in the shop use in there day to day.
On my old Buick (with big, beefy strut-to-knuckle bolts), I couldn’t get those bolts to budge with a big breaker bar. So I jumped on the breaker bar. The bar hit the floor and didn’t bounce back. I fell off. Surely, the nut had turned.
In fact, the socket had split down the middle. The nut hadn’t budged. It took two more days of penetrating oil and a new socket to get them out. Get an impact wrench and socket. 
Not really a tool, but essential just the same. The FSM (factory service manual). I’ve purchased one for each car I’ve owned, new or used. Order it from the dealer’s parts counter.
Battery operated rechargable LED work light. 50 or more LED’s would be best.
If you do not have an air compressor, one device that I received as a Christmas present was a Black & Decker “air station”. It is not only useful for keeping up the pressure in car and bike tires, but is useful for blowing dirt away from around the spark plugs and other places. I prefer this plug-in compressor to one that connects to the car battery.
Right now, since I am debating doing my own struts
What are you going to use to compress the spring???
There are good tools for this and bad tools for this. Personally I wouldn’t touch it. I’ve seen a couple of people try it without the proper equipment and got seriously hurt.
An air compressor and an impact wrench.
Also, I have screwdrivers with sliding clips on them to hold the screw heads (hold the screw on the screwdriiver). I hiughly recommend them.
Besides basic hand tools, these are some of the specialty tools I use that make auto service/diagnostics a lot easier.
Hard access hose clamp pliers. http://www.sears.com/craftsman-cable-operated-hose-clamp-pliers/p-00947390000P
Serpentine belt tensioner tool. http://www.harborfreight.com/serpentine-belt-tool-kit-66344.html
Inner tie rod tool. http://www.harborfreight.com/inner-tie-rod-removal-set-96558.html
Internal/external snap ring pliers. http://www.sears.com/craftsman-snap-ring-pliers/p-00945358000P
Hand impact driver. http://www.sears.com/shc/s/p_10153_12605_SPM1965760501P
Fuel pressure tester. http://www.sears.com/shc/s/p_10153_12605_SP101A12213S3876332101P
Compression tester. http://www.harborfreight.com/compression-test-kit-66216.html
SAE/metric thread restorer. http://www.sears.com/craftsman-48-pc-sae-metric-thread-restorer-kit/p-00942275000P
Damaged bolt/nut remover. http://www.sears.com/shc/s/p_10153_12605_00952166000P?mv=rr
Steering wheel puller. http://www.sears.com/craftsman-steering-wheel-puller/p-00941833000P
Steering wheel plate remover. http://www.craftsman.com/craftsman-steering-wheel-plate-remover/p-00941834000P
Cooling system/cap pressure tester. http://www.sears.com/craftsman-cooling-system-pressure-tester/p-00946342000P
Ball joint/tie rod seperator. http://www.thetoolwarehouse.net/p-4394-otc-6295.aspx
That should be enough to lighten the wallet for now.
Tester
I must of missed it because I can’t believe no one say a high quality clicker type torque wrench and some never-seize (to be used sparingly and carefully!)
One of these:
$25, including shipping, and it has been years since I’ve had to grab a hand tool of any kind to change my oil. I pull into the garage after work, get out, pop the hood, slide my pan under the valve, and I simply reach under the car and flip it open. No wrench needed, and no risk of stripping or crossthreading anything. Go inside, eat dinner… come back out, close the valve, spin off the old oil filter, spin a new one on, and refill the oil. I can change it in less time total than I can drive down to the nearest shop of any sort and come back…
Decent sockets, ratchets, and breaker bars in 1/4", 3/8", and 1/2" drive sizes. A lot of times bolts that shouldn’t be hard to break loose are, and 1/2" breaker bar will get them loose a lot more easily. This should also include deep-well sockets.
Find what kind of oil filter wrench works best for your situation. I have Channel-Lock oil filter pliers. Different cars have oil filters in different places, and there isn’t really a one-size-fits-all there.
GOOD QUALITY screwdrivers, slotted, phillips, and torx. Cheap phillips screwdrivers are useless. Cheap slotted screwdrivers aren’t much better.
I know it sounds like a lot of money, but a 30 gallon oil-lubed air compressor can be had for a bit over $400 at Home Despot. Once you have one, you’ll be amazed at how nice it is to have around. Air tools, particularly a good 1/2’ drive impact wrench (mine is an Ingersoll-Rand 231 C) are handy, and while a GOOD impact wrench might set you back $150, a lot of air tools are not real expensive. The oil-lubed compressors with the big belt-driven flywheel are much nicer than the oil-free models. The oil-free models are obnoxiously loud, and most of them won’t keep up with a die grinder or cut off tool.
Between me, my wife, and 3 kids there are: 5 bicycles, a couple beach balls, a dolly with pneumatic tires, and 2 cars. I have a fairly frequent need for compressed air, and it is nice to be able to simply grab an air hose in the workroom.
Minor tool but I love my B&D AA battery screwdriver, 8 bucks at target. I am so burnt out on rechargeables, I bought a new one, as a summer helper messed up my old one. I was tracing conduit for new network wiring and suggest he keep tapping on a pipe with a screwdriver so I could locate it, Big regret when I found it was my B&D. unfortunately they shortened the shaft so a double sided bit will not fit. I have a kit with drills and sockets, and for regular handywork it is my most used tool. Also a 17/32 socket, I think for when you loose all the 14mm sockets :}