N. Korea vs. S. Korea Who will win?

On their own:
North Korea

With their allies:
North Korea (China, Russia, Iran etc) South Korea (America, UN - who are basically useless, Japan - SK have no major European allies, so the three major European superpowers of France, Germany and the UK won't really help them that much, probably just vocally condemn the actions of N Korea)

I suspect it would be the North. I read a paper about their military capabilities and, if everything detailed in the paper is accurate, they are very powerful indeed. A vast tunnel network with millions of tonnes of fuel and food, tanks adapted for hilly terrain, missiles that would destroy that US carrier fleet, surface-to-air missiles that would annihilate Apaches, not to mention the sheer, highly motivated manpower... apparently the US army could be wiped out within 3 hours. US bases situated near the border in South Korea would be obliterated and it would be a total mess.

Their unknown nuclear capability and its potentially devastating results if utilised would be another thing altogether.

How you doing Kim?

They are almost bankrupt, they rely on aid to survive and their military is almost their entire economy.

The only advantage they have going for them is tactics and location, nothing else matters - Nuclear weapons; there's no proof they have them in any form that they'd be able to use (i.e missile), nor is there proof that they have the technology. The only proof we have is a seismic chart or something similar, which could have been created by a normal explosion of vast quantities.