It's only through luck and concessions that Sweden maintained their "neutrality" in WWII. Everyone had their eyes on a prize somewhere else. Had things gone differently between Germany and the Soviet Union, Sweden may have found itself divided up by both.

Switzerland also made concessions to stay out of the war. Germany wanted to invade, but the risk/reward wasn't worth it at that stage of the war.

Spain was in a civil war and I wouldn't call their post war situation a "success."

Ireland, I guess you could say, faired okay after the war, but during the war, their ships were attacked by both sides and often received no response to distress signals.