Many people have asked which side I liked the best. For me as a photographer you should not neglect seeing each side of the falls. As mentioned above, the Brazilian side has all the panoramic shots. The Argentina side has all the up close and personal shots. You would be doing yourself a huge disservice if you skipped out on either side.
The parks are not photographer friendly though. They open up at 8am and close at 6pm. So forget getting that crack of dawn shot. And unless you go in the winter time, you will not be getting that perfect light for sunset. I was pushing it getting my shot and the park ranger eventually ran me out of the park. I was the last one to leave. I did not fly thousands of miles and spend thousands of dollars to take crappy shots with poor light. So I had no problem pushing it right up past closing time.
If you want to avoid this you will have to splurge and spend the extra money and stay at the Sheraton on the Argentina side or the San Juan Hotel with in the park on the Brazilian side. I will do this next time I go. And I do plan on going back.My trip to Iguazu Falls this time was a gutsy one.
I rented a car and drove from Sao Paulo to Foz do Iguaçu. Took us around 19 hours of driving mostly single lane highways and over $100 worth of toll roads. Brazil does not have a rail system like America so they have crappy semi trucks clogging the highways that you will be fighting with over the entire trip.