assortment of cheater bars... absolutely required. I bought about half a dozen odd lengths from the bin next to the pipe cutter/threader in the pipe aisle at home depot. A 4 foot long piece of 2" black iron is GREAT with a large monkey wrench when you're putting a pinion nut on.
Full torx set.
This really neat rechargeable LED work light that home depot has in the work light section in one of the electrical aisles - comes with an AC charger and a lighter plug charger, I keep one in each Jeep now because I'm tired of crappy chinese flea market flashlights dying on me.
Keep a random bald tire on a crappy rim around, great when you need to take the nut off a stub shaft + unit bearing and don't want to put the thing in the vice, I just thread a couple lugnuts onto the studs most of the way, sit on the tire, and crank away with my breaker bar and a cheater bar. Works every time.
An engine hoist or a sturdy hook in the ceiling and some rope + block/tackle are great. I use my engine hoist to lift things out of the back of the MJ when I'm too lazy to do it by hand now - great for unloading axles alone, etc.
An assortment of mallets and hammers is good too, I used to be the guy who only used a small carpenters hammer on everything, then I got a 6lb hand sledge (actually a blacksmith's hammer) and found out just how much easier it is to knock a unit bearing out with a hammer of the right size.
EDIT: oh yeah, the OEM brand pitman arm remover at AutoZone is great, well worth the $15 it costs. I use mine to pop the tie rod off the drag link without mushing up the crown nut or the TRE threads. A good gasket scraper (the kind that uses a straight razor blade) and a set of brass and steel punches are also required. Drill press is great to have, I use mine for way more than drilling, I made all stainless screws for the bezels on the front grille by taking panhead screws, putting them in my drill press, spinning it up and using a file till the heads were the same size as the rusty OEM fasteners.
EDIT2: ... safety glasses (and if you wear glasses, a face mask) are REQUIRED! My insurance company has paid at least 1500 dollars to the ER so far and the bills are still coming in... all due to a 0.1mm fleck of metal that found its way past my glasses on new year's day while I was using an angle grinder. It would be at least 6k out of my pocket if I didn't have insurance. Learn from my mistake on that one.