Ernest Shackleton: What Shackleton lacked in, well, success, he made up for in superhuman determination to get his men home. Leaving his team on Elephant Island after their ship Endurance was crushed by ice on October 27, 1915, Shack sailed a whale boat 800 miles through ferocious seas for help.
Robert Peary: Peary realized that in order to survive the brutal Arctic, explorers had to adopt Inuit attire and igloos (although not, apparently, the children he sired among their womenfolk). Only two of his toes survived his repeated attempts at the North Pole, but in 1909, he claimed to have finally made it.
Fridtjof Nansen: After skiing across Greenland, Nansen froze his ship Fram into an ice pack in 1893 and let it drift north. Realizing he'd never drift closer than 84.4 degrees latitude, he set out for the pole on skis, only to have to turn back. He finally made it home to Norway in 1896, shortly before his ship.
Roald Amundsen: It took three winters (1903 to 1906) to get through, but Amundsen was first to successfully navigate the Northwest Passage, spending his downtime learning Arctic survival skills from the Inuit. He then skied 400 miles to Eagle City, Alaska, just to send a telegraph to Norway to say he'd made it.