I would much rather go to some place in Europe than South America. I'm afraid I'll catch some kind of horrible disease down there.
Visit Costa Rica. It's awesome, though not technically in South America.
The natural beauty of Costa Rica is astounding, and there are lots of cool plants/animals to see, but I enjoyed the culture of Peru so much more.
On second thought, that may be because I stayed in a hotel in Costa Rica and I spent 6 weeks living with a family in Peru and staying in hostels when I traveled.