Beheading is considered to be barbaric/savage. INSTANT GONE no suffering. No torturing. No lingering. Merciful isn't it?

I think beheading is a good idea. I'd like to see what the back of my head looks like when it falls in the basket. 
Err... Wait a minute..

Put the mail in the basket - I'll read it later. 

I think it might be preferable to being hooked up to the electric chair, especially if it doesn't work the first time they pull the lever.  We've also heard about that injection they give you that fails to do the job and you're paralyzed but not dead.  Frankly, I don't know why they go through such elaborate things when all they have to do is inject an air bubble into the arm.

Former French executioners reckoned beheading even with a guillotine amputates the head instantly, but it does not die instantly.

Even if it did, it's still a revoltingly gruesome and barbaric method.

I don't know if being hanged by gallows (not "hung", nor by gibbet) is any quicker, though it's said to be instant.

The air bubble in the arm is not guaranteed to do anything other than induce an appalling attack of "the bends".