UR R26R.5, VW Golf R
Loads of maths in this game, lol, I don't sneak so no puffy dagger for me, big Sword and big Amour, wade in and hit them hard but those stats suggest that thief and sneak look very powerful.
Well, like I said, I've got Archery and Sneak levels up (60+ and 90 respectively). The damage you can do with the bow while in sneak mode is incredible. It can easily take out high level bandits, animals and mage's with one shot, 3x sneak bonus. Couple that with 50% slow motion perk while zooming using the bow. Awesome.
Here's the perks for Sneak :
http://elderscrolls.wikia.com/wiki/Sneak_(Skyrim)
I've got them all up to Silent Roll, so that includes Deadly Aim (3x damage with bows). I didn't take the Assassin's Blade perk as I don't use the dagger, but you can see there that it offers 15x damage!