Luthor's Lair #5 shown in Superman #170.
Nefarium an underground Luthor Lair was used in (Action Comics #510).
Neutron uses the abandoned Luthor's Lair #16 (Action Comics #526).
In "Hero for a Day--?" Lex Luthor takes over Linda Danver's tree in the town of Stanhope where she hid her Linda Danver Robot and he turns it into Luthor's Lair. (Action Comics #486)
In "Welcome to Luthorcon III!" Lex Luthor had a flying pyramid ship as a hideout. (DC Comics Presents Annual #4)