crown jewels

from Wiktionary, Creative Commons Attribution/Share-Alike License.

• noun literally the jewelry that accompany the office of rulership in a monarchy. I.e., crown, scepter, signet ring, etc.
• noun A prized possession or asset
• noun A part of a company sought by another in a hostile takeover
• noun idiomatic The male genitalia

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

• noun regalia (jewelry and other paraphernalia) worn by a sovereign on state occasions