Puerto Iguazu is the Argentinian town closest to the falls.
The Argentinian side of the falls is a bigger attraction when compared with the Brazillian side. You can visit the Brazil side in about 2 or 3 hours but on the Argetinian side you need about 5 or 6 hours. There are more trails, activities and even a small train ride to get to some of the viewing platforms.
It really is best to visit both sides to take in just how massive and awesome the falls are.
Puerto Iguazu was also our home for New years Eve. There was nothing going on in town and nobody was at our hotel bar so we had a party in our room, with some good wine, snacks and the cable movie channel!