Best series ever on many levels, the highest of which is the portrayal of integrity in its two key forms: one, a willingness to engage in vigilante justice while maintaining integrity (John Reese) and two, a need to follow the law, but to make exceptions where needed to maintain one's integrity (Detective Carter).
The secondary, but by no means inconsequential level, is the portrayal of omnipotent and monolithic government with the power to control every aspect of our lives. That it took one man, Harold Finch, as an individual and one opposed to leaving such power in the hands of those he knew would abuse it, to prevent the ability to use that power.
Simply the finest series ever made for those looking to watch true heroes in action.