In the world of tiny pocket tools, this one from Swiss+Tech has to be one of the oldest on the market. By this point, it's a classic, and I think it was actually my first. In a small keychain format, it packs two hex wrenches (1/4" and 7/16"), six screwdrivers (three Phillips and three flat), a pair of pliers, bottle opener, wire cutter and stripper, and wire crimper. There's also a built-in file, two rulers, and a hand drill. And when closed, the arms lock the hex opening in the pliers closed, making it function as a keychain.
If I'm going to be honest, about half the tools are so small they're not going to be a ton of help in most situations. But at its current price, it's tough to complain. Currently, you can grab a two-pack of the Swiss+Tech Micro Pocket Multi-Tools for just $4.99 as an add-on on Amazon. Normally, one of the multi-tools goes for just under $10.