I had been using a single handed sword originally, and using sneak to backstab foes resulted in the super-sweet throat slit animation nearly every time. Ever since switching to dual wielding axes, I haven't seen a single kill animation whether I'm backstabbing or performing straight on in-battle kills. Are there no kill animations for dual wielding, or do I need to switch to swords, or is it something else entirely?

finishing moves trigger on crit hits, and daggers/swords have the highest crit chance. your just unlucky.

Keep in mind that the animations will only show if you kill lone enemies, or the last of a group.

If you're on the pc, try typing:
set killmoverandom to 100
in the console and see if that makes a difference.

I have seen this stated before, however, on many occasion have I executed a character whilst being beaten on by another.

Yeah, if you get spotted during the animation, you can be attacked. Bit annoying when it happens.

I have seen from experience that dual-wield just gets less finishers. I speculate it is because dual wield uses so many animations and some of those must be interrupting the cinematic.

Regardless yeah, One handers get way way more (finishers) than a dual.

First off the "Stealth Throat Slitting" is for swords and daggers likely, and I've had plenty of finishing moves that I doubt would happen when not dual-wielding

Are there finishers that actually use both weapons - as in They were put in specifically for dual wielding?

I've seen one, two swords scissoring off an enemies head. It was epic.

Every weapon has it finish moves. If you want to know.. CENTURION MASTERS.

You got a dual wield finish animation for the centurions. You cut both legs of the machine and it falls.

And, yes, you have finish animations for woodcutter's axe and PICKAXES! The pickaxe does a "pickaxe in the face" animation.

There are PRETTY much animations for finishs for many weapons.. You must be unlucky, that's it.

The most silly finisher has got to be a mace decapitating the opponent with the same sound and animation as a sword. I mean, seriously? And the cut was even clean. With a blunt instrument. WTF?

Same thing with mace finisher vs dragons. It just screams "Hey my mace is a sword"

This is false. I fought 3 bandits and chopped off the first two opponents heads and then ran the last through with my greatsword and lifted him into the air.

The head-chop is the exclusion to the rule, since it occurs due to a perk and is not part of the regular execution animation set.

I followed a group of four people and slit their throats one by one while sneaking so I think its more random/critical hit.

The giant kill animation with dual wield swords is by far the coolest one I've seen. You slice the leg just behind the knee with the sword in the left hand moving from right to left (I believe) the giant drops to his knee and then in the same motion you take the right hand sword and shove it through the bottom of his mouth and out the top of his head. It was freaking awesome.

Do you do this by using the "click both buttons simultaneously" dual wield attack? I almost exclusively use that since it does more damage, and still I haven't seen my character perform a finisher since leaving the caves of helgen. Does soul trap cancel finisher animations? Do enchanted weapons cancel finishers?