Highest ranking bands with highest ranking album by year:
Judas Priest (6) --> A better performance than Maiden's 6, since this happened on an Iron Maiden fans forum.
1977 - Judas Priest - Sin After Sin (#28)
1978 - Judas Priest - Stained Class (#13)
1982 - Judas Priest - Screaming for Vengeance (#16)
1980 - Judas Priest - British Steel (#14)
1990 - Judas Priest - Painkiller (#5)
2018 - Judas Priest - Firepower (#82)
Iron Maiden (6)
1984 - Iron Maiden - Powerslave (#2)
1988 - Iron Maiden - Seventh Son of a Seventh Son (#1)
2000 - Iron Maiden - Brave New World (#10)
2006 - Iron Maiden - A Matter of Life and Death (#9)
2010 - Iron Maiden - The Final Frontier (#111)
2015 - Iron Maiden - The Book of Souls (#56)
Black Sabbath (5) (maybe 6 if we can count their debut as well, if that was the 2nd best from 1970! ;--) )
1970 - Black Sabbath - Paranoid (#23)
1971 - Black Sabbath - Master of Reality (#18)
1973 - Black Sabbath - Sabbath Bloody Sabbath (#50)
1975 - Black Sabbath - Sabotage (#105)
1981 - Black Sabbath - Mob Rules (#44)