I wouldn't really call it "idiot proof", but it is SO TOUGH that even klutzy me has yet to make a dent in it.... the Totally Wicked Vape-Pro... VERY solid/sturdy metal construction, one solid piece with no seams minus the screw in cap for the battery. I've dropped it many, many times on concrete AND a very hard bare floor and it still keeps on ticking like the day I bought it... just don't get the black chrome version, it's a thin coating that scratches easily. Runs about $100 for the body but it is SO worth it! American made too so you know the quality control is tight... and TW has awesome customer service... it also comes w/ a 6 mo. warranty.
Another really tough APV I can think of is the Lavatube. I don't know tons about this one since I'm not an owner (just have friends that have them), but it is definitely a little more idiot proof than the Vape-Pro, only having variable voltage and no other settings.
And the winner for idiot-proofness is the Bolt. Also not an owner, but again, got friends with this one. No settings at all, just a button for making vapor. Cheap yet just as tough as the others.