Portrait of a Young Man (above), now in the Louvre, gets my vote as the most vivid of Giovanni Bellini's portraits, "swathed in a still, rarefied air" as one of the more mellifluous sources asserts.
Most of the images originated here. Hard as it may be to believe, I still have not finished with my Giovanni Bellini obsession. Upcoming, a discerning selection of non-male figures.