Not sure what kind of cookbooks you're going for here, but here are a few staples that hold a kitchen together:
the Company's Coming cookbook
The Joy of Cooking
Betty Crocker Cookbook: Everything You Need to Know to Cook Today
The Barefoot Contessa Cookbook
Mastering the Art of French Cooking
Rachel Ray has a 365 no repeats one that I hear is awesome, but haven't tried yet.
Hope this helps! :)