Quito - Why?
If you like churches then you may like Quito. However, it is mostly urban sprawl and I wouldn't recommend staying more than two nights (two full days is more than enough). It was the first World Heritage listed city but honestly, it isn't THAT nice. There are better places to go in Latin America, or if transiting through, minimize time here.
Insider Tip:Avoid La Mariscal, its dangerous, touristy, tacky and expensive, stay in Old Town which is closer to the historic sites and La Ronda which is where the locals spend their nights eating and drinking.