That is because Enterprise is the oldest name in U.S. Naval history.Copper Zen said:"Enterprise", of course. It was the first space shuttle [http://en.wikipedia.org/wiki/Space_Shuttle_Enterprise] after all.
The funny thing about the Star Trek series is that even non-trekkies wouldn't blink if we named a starship "Enterprise". If we named it "Millenium Falcon" on the other hand people would roll their eyes and balk.
The 8th vessel to carry the name is a Nuclear Aircraft Carrier which is only recently decommissioned: http://www.enterprise.navy.mil/
My names would be more based on their intent. Warships would have names like Fearless, Indomitable, Courageous, Dominant, Chimaera (Star Wars reference), Valiant, and Virulence (another Star Wars reference).