Ice melts raise ocean levels when they start on land. Ice in the ocean has already contributed to sea level and can't be counted. That means the entire North Pole doesn't count.
So, that leaves Iceland, Greenland, Antarctica and parts of Canada like Baffin Island (which has its own icecap).
Greenland is the real threat since measurements have proven the recent mobility and melting of its icecap ... which itself seems rather responsive to so-called Global Warming. If it melts at least halfway, ocean levels would rise about 10 feet:
http://www.google.com/search?hl=en&q=greenland+melting+ocean+level
Antarctic ice shelves have been letting go recently, but since those are largely oceanborne, they also don't contribute to a rise in ocean levels. However, those icebergs are providing an increasing hazard to shipping.