Radio astronomy is entering a "Golden Age". With plans for the Square Kilometer Array now shaping up well, new facilities are already being commissioned (ALMA, Lofar) or receiving substantial upgrades (e-VLA, e-MERLIN, e-EVN). This improved instrumentation will provide new opportunities for many areas in astrophysics and cosmology, including the study of Active Galactic Nuclei. I will focus on two case studies, presenting recent results and possible developments: on the radio bright hand, I will show detailed Very Long Baseline Interferometry observations of the jet of the radio galaxy M87, which reveal interesting elements to constrain the location of the high energy emission region and of the jet formation; on the radio quiet side, I will report the recent detection of compact radio sources in the cores of several low luminosity AGNs, discussing possible physical interpretations and future prospects.