Some of the best fun I've ever had was getting into "gadget wars," which are essentially just trying to "out-gadget" someone else or another group of people. Even leaving out the competetive aspect, it's just fun to see new gadgets! There was even a time when the latest gadget brought to the battlefield was the keychain LED light (on a backpacking trip MANY years ago, no less), and of course Spyderco knives have always made an amazingly strong showing at these little throwdowns as well!
It's been a while since there's been a good showing of gadgets, so I'll start with something that's not TOO strong, but still one of my all time favorite gadgets:
THE ELECTRIC FLYSWATTER!!!
I only post the website because I'm not sure how sensitive this company would be to me using a link to their picture. Didn't have any good pictures of my own...
Sure, there's a number of companies that have designed and produced their own variations of this awe-inspiring little death dealer, but evolved technologies aside, there are few things more gratifying than watching that irritating little mosquito (that's been stealthly eating you alive) explode into an electric spark mid-flight
There are yet more gadgets in my arsenal, but I'll save them for later