We aren't always. Although when writing a letter or an email to a person that you don't know, you would use the last name... it is actually more common in most parts of American society to refer to...
Well over 100 vessels to name, but here's some important ones:USS Yorktown, USS Hornet, USS Enterprise, USS Lexington, USS Saratoga, USS Wasp, USS Princeton, USS Gambier Bay, USS St. Lo, USS Bismarck...