I've found 2 pieces of electrical medical quack machinery at thrift stores, one is a violet wand and the other is, well, difficult to explain. I still have it but it's a weird thing that is supposed to match your body's impedance and then alter it by adding more electrical power to you.

I've also found sterling silver bowls, one from the late 1800s, old copies of the Bible, first edition signed books, rare out of print books, like foxfire 1-6, pre-german reunification beer steins, uranium glass, tools, a working pump for a Jacuzzi spa, vinyl records, an HDMI upscaling combo vhs DVD player, clothes, lights, advertisements for the 1977 movie Wizards, musical instruments, sterling silver, gold necklaces, computer parts, karaoke machines, German cuckoo clocks, Picasso prints, a Christmas deer that looks like something out of the Deetz house post renovation from Beetlejuice...

It's fair to say I thrift shop a lot, but I've found a lot of interesting rareties.