While there is some debate as to who is the most important religious person in the world, there is little doubt where the most impressive art collection in the world is, Vatican City. Home to the Pope Benedict XVI and the Sistine Chapel, it is easy to forget that the whole Vatican City is art housing more art.
While I am personally uninterested in the goings on of the church and its philosophy, I would have to say that a visit to Rome would not be complete without spending a good chunk of the day in Vatican City. From the buildings to sculptures to paintings, it is all on some level artistic perfection. I cannot suggest strongly enough that rushing to from the museum entrance straight to the Sisteen Chapel is a huge mistake. I know some guidebooks recommend this plan of attack to beat the crowds in the morning, but the collection of paintings and tapestries are beyond extraordinary. Take your time. I am not sure why I love the top photo, but I do.
The honorable mention photos below include indoor and outdoor lighting that, for me, made the images that much more impressive.