From Foz do Iguacu, I took a public bus to its Argentinian counterpart Puerto Iguazu. From there, another bus brought me to the falls.
This side also has some theme park-feeling. I did give in this time, and joined the Great Adventure. That's when you cross the forest by giant car and then jump into a speedboat. The boat takes you up close to the falls, and somewhat underneath. I got terribly wet and didn't dry until I got back to my hotel in the afternoon and could change clothes.
Somehow the falls look smaller from the Argentinian side. However, strolling through the surrounding forest is very worthwhile here.