Most of my favorite tools do one thing and do it well.
* Swiss Army Knife (now called the 'Spartan' - no frill bullshit). I've redone entire racks of equipment with only this at my disposal and it's not fallen over where multiple others (such as leatherman and gerber) and have had no problems. I've also done god knows what else with them - I've had a total of 2 in the past 25 years as "always in my pocket", and both still work.
* IBM Model M - goes without saying. They don't break or die.
* Compaq iPaq desktop - hey, mine is still kicking and working like a champ on my network. Not a fancy billed item, but I've had mine working continuously as a small home network services system for over a decade now, and it's reasonably power efficient even by modern standards.
* Brother ML1345 printer - black and white laser. Still kicking.
* Nintendo Gameboy - the original. Built like a fucking tank. Mine got run over by a Ford F150 and still works: my kids use it.
* Hitachi hard drives: they're the best out there. I've never had one die and have owned dozens personally.