No need to hire..they will probably charge an exorbitant amount. I would do a. City Center (Plaza de Armas, Catedral, Palacio de Gobierno, etc), or b. Miraflores. My answer depends on whether you have been to Lima before. Option a. is about 30-60min drive, depending on the time of day, and lots to see. Touristy as it holds the colonial past of Lima and you can eat/shop at relatively cheap prices. Option b. is a bit farther at about 1-1.5hr each way. You can get of at Larcomar (shopping/restaurants) and walk around. One more note, if your flight out of LIM leaves late at night: the later in the day it gets, the harder it will be to find a taxi. Basically, the later it gets and the farther the distance, the less they are willing to drive. Good luck!