I thought I'd sign praises for some products I've come across. Off the top of my head in no particular order.
The term "built like a tank" pretty much qualifies. Match needle metering is very nice. The shutter speed ring can be a bit odd. 625 battery is certainly a downside, but it appears to work quite well with just an LR-44 dropped in.
Today: If you can afford it and want all-manual film, this is an excellent option.
It was the cheapest (D)SLR body in the market at the time. It's turned out to be a real jewel. Conservative design cut down. Small and light but comfortable to use. Well thought-out and fast operation, most options at your fingertips. Comfortable size screen. Last model made with this sensor, so quite likely the best model made with this sensor. Many seem to think this outclasses many "pro" bodies that are cumbersome and bulky and the extra features aren't worth the huge price leap. That probably depends on the features you need. Fast 1/500 top flash sync speed. Fits almost every F-mount lens ever made (including pre-AI!) plus anyhing else you can safely attach of course. Doesn't do D-TTL (does i-TTL), screw drive AF (does AF-S), or AI metering (does electronic metering). Sadly not stop-down metering either.
Today: Still as good as ever. Discontinued but you can still find some and they'll be very affordable because it's seen as an old low-end camera. 6mp is sufficient for me. Easy to carry but not a pocket camera. Depends on your use. No dynamic range trickery, auto bracketing or LCD viewfinder. Perfect mate for any 50/1.8 Nikkor or 100/2.8 Series E!
Vintage Micro-Nikkor 55/2.8 AI-S
I paid a fair bit for this and whatever it was, it wasn't enough. This is a dream. All micro-Nikkors are spectacular and 55mm is a very general purpose one. Reliable manual action, f/2.8, very very long throw focus ring. Good working distance. Scary sharp. Absolute dream lens for closeups.
Today: As good as it ever was, unless yours has been damaged by oil migration, physical trauma or excessive use. And even still it probably works and may be repairable. Today, old models (and there are only old models, the new ones are a different splendid animl) can occasionally be found for very reasonable price. You can't have mine.
Nikon SB-20 Speedlight flash
Funky old-ish unit. Auto flash in several steps (set ISO and aperture). Manual flash in several powers. PC sync connector. Pretty good power. Vertical bounce angle with odd rotary head, three fresnel patterns. Probably does D-TTL too, I don't know. Bulletproof exposure for many ranges and subjects.
Today: A real winner for off-camera and other manual use along with SB-28 and some Vivitars. Handy bounceable flash. A bit bulky perhaps. Seems reliable. Low trigger voltage of course. Subtitute another good flash and you still get a lot.
Asus P2B motherboard
ECC ram, Piii with a little overkill cooling. Quite possibly the most stable "beige" PC ever. Affordable x86-ricer cpu power in its day.
Today: Quite obsolete. Pci isn't compatbile with everything, little underpowered and slot1 has no upgrade path. USB1.1, UDMA33.. And it's still just a pc.
Small belt-clipped plastic box with screwdriver bits and an extender. Size of a matchbox or so and attaches together as a handy screwdriver. Saved me a lot of trouble as a sysadmin and I still take it along occasionally. You can switch some of the bits for strange ones if you need them. I have a hex bit for furniture and a torx that fit certain compaq parts. It was cheap, too, IIRC.
Today: Still working perfectly though it's probably easy to damage the plastics with excessive force. You can probably find various models and variations of this. They're a good idea. Swiss rmy knives and multitools aren't. They just don't work.
Miltec civilian version of a bundeswehr shoulder bag
Black, square, has no clips or obnoxious bits. The shoulder strap ring has a tendency to turn sideways if loaded. I've added pockets for a cellphone and pen case. Inconspicuous and practical.
Today: Better than new with the pocket hack. Carries books, Ti-86, bags, clothes, tools, smaller laptops, cameras and whatnot.
Frost's #121 knife (puukko)
From the "perfection is achieved when there's nothing more to remove" school of design. Sure grip, good sized blade for woodwork. Very accurate to work with. When sharpened properly, very sharp and still durable. Sheath is the swedish utilitarian plastic type. I've made a new one for fun.
Today: As good as ever and best I've met.
Kenwood Trio oscilloscope
Well, any old (or new, but older ones are affordable) scope in good repair. Doesn't have flashy features and sometimes you miss storage or image capture, but that's the way it is. Takes some space, too. I've wanted one since the 80's and I wish I would have gotten one earlier. Full repair manual available from BAMA or some other source for some models.
Today: Still works perfectly. Lets you do a lot of basic measurements and observations.
I'll see if I can come up with more and add some links later.