Thanks for the reminder King Edward. In the "modern" era, the A-10 is one tough cookie and its ugly look has a beauty all its own. Once I was sitting in a traffic backup in a rural Pennsylvania valley when two A-10s flew by at very low altitude down the valley. It was a thing of beauty that sent chills down my spine.

The Hind helicopter mentioned by Redleg is another good one. That is one mean helicopter that I'd probably refuse to take a shot at no matter what I was armed with simply out of fear that the only damage I'd do is to piss it off. (Side note: as I write this, the washing machine has gone into its spin cycle and it sounds an awful lot like a helicopter - run! )