GSMarena mobile camera shootout(Lumia 1020, Galaxy Note 3, iPhone 5s, Xperia Z1, LG G2, HTC One)

http://www.gsmarena.com/six_way_camera_shootout-review-998.php

They are all surprinsingly close. The definite best is the Lumia 1020 obviously, but they all have their strengths and weaknesses. The HTC One sucks in anything other than low-light, tough. Oh and finally for those Apple fanboys saying: "nothing comes close to iPhone cameras", think again.