From a nostalgic heirloom sort of perspective, my favorite tool is an old (late 60s) power drill my dad bought in the late sixties from K-mart.
My dad used it when he finished off the attic in the house I grew up in, at that time I was young enough that I was forbidden to touch power tools, but I was of course fascinated by anything that moved fast, made noise, and could make holes in things.
I remember my soon to be brother in law using it with a sanding disk attachment to strip the paint off the tank and fenders of a Honda 350 (remember when those were everywhere?) he had bought to fix up in the early to mid 70s.
I did the same, using it to strip paint and smooth filler on a rusted out MGB/GT I repainted in the early 80s, and used it with a 3M abrasive wheel (the kind that looks like a sponge and strips paint and rust) when I re-did my TR4A in the early 80s.
It drilled holes for the sway bar install in my brother's Sprite somewhere back in time too.
Plus drilling out innumerable rusted out nuts, and standard use for various carpentry projects.
The thing just won't die, it has a metal case like they used for all power tools back then, it did have a three prong plug, but I broke off the ground when I was young, poor, and stupid and didn't have an extension cord with a ground wire.
It was semi-retired when the wear in the bearings made it a little harder to drill a precise hole, but put back in service from time to time when the later model drills I bought (admittedly cheap ones, but so was the K-mart drill) gave up the ghost after doing less than a tenth of the work old reliable has done.
The last couple years I made a special place for it atop the peg board in my garage, but it stays there, ready for further duty when lesser tools inevitably fail.