324 Bamberga
Although its very high orbital eccentricity means its opposition magnitude varies a lot, at a rare opposition near perihelion Bamberga can reach a magnitude of +8.0, which is as bright as Saturn's moon Titan. Such near-perihelion oppositions happen on a regular cycle every twenty-two years, with the last happening in 1991 and the next in 2013. Its brightness at these rare near-perihelion oppositions makes Bamberga the brightest C-type asteroid, about one magnitude brighter than 10 Hygiea's maximum brightness of around +9.1. At such an opposition Bamberga can in fact be closer to Earth than any main belt asteroid with magnitude above +9.5, getting as close as 0.78 AU. For comparison, 7 Iris never comes closer than 0.85 AU and 4 Vesta never closer than 1.13 AU when it becomes visible to the naked eye in a pollution-free sky.