The peak of maid manga came at the beginning of the millennium, when literally any doofus could make a ecchi manga, throw some maids in it, and call it a day.
HANAUKYO MAID TEAM (Hanaukyo Maid-tai), by Morishige. First published in 1999 and first published in North America in 2003.
STORY:
Tarou didn't know what to expect when his dying mother bid him to go to his grandfather. He didn't expect his grandfather to be fabulously wealthy with a giant mansion full of horny maids to cater to his every need. He definitely didn't expect said grandfather to leave everything to Tarou. Now he has to learn how to navigate his life with an army of maids who create a lot of chaos in their attempts to manage every detail of his life.