Peru is a very beautiful country that has a lot to offer. It is easy and very comfortable to be a turist in Peru - unfortunatly this is due to the mass tourism in the country.
Lima is a "love/hate" capitol and I LOVE the city. Long sandy beaches, sweet people and beatiful buildings. We came back to Lima several times and each time we stayed at the crazy and somewhat weird Quique, which we came to care for. Take a stuffed minibus 20 min. south of Lima and you will find small villages and long deserted sandy beaches!
Cusco must be the most beautiful city in the whole wide world. The city it self was a lot more impressive than the Inca ruin of Machu Picchu it self ...Cusco has everything!
Lago Titicaca was special, but over advertized, touristy and overrated, which also goes for the beaches in the northern Peru.

Peru, like Ecuador, has everything: beaches, mountain, jungle, cold, warmth, etc. The country is pretty well developed when it comes to tourism and therefor it is rather easy to travel in the country. Of course it also means that there's a lot of tourists there and therefore one should def avoid high season. It would be a shame not to be able to enjoy the countries many pearls because of the masses...

Lima
Cuzco (at least one week for the city it self)
Machu Picchu
Arequipa (Colca Canyon)
Lago Titicaca
Máncora (overrated)

The Peruvian people are beautiful, creative and happy!