If you are a man, your favorite tool is a hammer. If not, turn in your man card now! That said, I am a man of wealth and taste so my favorite tool is a pair of fencing pliers. Now before you metro- types ask for my man card yes they are pliers and yes they are designed to be used as a hammer and prybar. In short, a pocketful of destruction.
Other than that Vise-Grip makes a multi-tool with a weird pelican-type jaw, grips all kinds of stuff and it also has a knife, file, and a hex socket to accept bits. That, coupled with a big multi-bit set, a pair of fencing pliers, some duct tape, and safety wire can fix all manner of stuff. I do not even bother with electric wire in a car repair kit, there is so much non-essential wire in a car that you can get a piece if you need it.
