Four candidates ran and the two who made it into the run-off are both questionable. The run-off candidate with the most votes was leftist Ollanta Humala, and running second was Keiko Fujimori, daughter of an imprisoned former president.
All four candidates received substantial numbers of votes. The question of how people who voted for numbers three and four will vote in the run-off is very critical.
Ollanta Humala concerns the Peruvian business community as he is viewed as a populist/leftist somewhat in the mold of Venezuela's Hugo Chavez. It is feared he would nationalize natural resource-based industries and destroy the Peruvian economy, much as Chavez has done in Venezuela.
Keiko Fujimori concerns voters because her father's regime was both corrupt and somewhat repressive. On the other hand, father Alberto Fujimori is also popular with Peruvians as he managed to largely eradicate a violent, home-grown Maoist movement called Sendero Luminoso. His daughter claims her father laid the ground work for the subsequent economic prosperity; I'd guess she is correct.
Peruvian voters' choice boils down to increased equality without much prosperity versus more prosperity accompanied with more inequality. Add in how the voter feels about Fujimori Sr. and you've probably got the decision model.
My message to the Peruvians: don't feel like the Lone Ranger. The U.S. has been faced with choices between less-than-stellar presidential candidates for two decades or more. You hope you choose the lesser of two evils and get on with life. Sources for this post include this from Reuters, and this from The Wall Street Journal.