The plaque of the original Enterprise. Starfleet tended towards more simple designs in the 2260s.
The Enterprise-A plaque, showing basic information about the vessel's construction.
The Enterprise-B plaque included names of many of the Starfleet personnel who built the ship.
The Enterprise-D plaque remained essentially identical to that of the Enterprise-B.
The Enterprise-E plaque.
The Excelsior plaque shows the ship's motto, "No matter where you go, there you are..."
The Nebula class USS Sutherland's plaque bears the motto "There will be an answer, let it be..."
The Intrepid class Voyager's plaque bears the motto "For I dipt into the future, far as Human eye could see, saw the Vision of the World, and all the wonder that could be..." a quote by Alfred Tennyson.
The Defiant plaque. The first of her class, the Defiant bears the motto "All I ask is a tall ship, and a star to steer her by..." from John Masefield's 'Sea Fever'.
The Prometheus plaque. Another class ship, her motto is "All the world's a stage and all the men and women merely players, they have their exits and their entrances and one man in his life lays many parts; his act being seven stages.".
Another Defiant class ship, the USS Valiant. The motto is "We set sail on this new sea because there is new knowledge to be gained and new rights to be won." by John F. Kennedy.
Even smaller ships can have a plaque. This is from the Cousteau, the Captain's yacht of the Enterprise-E. The motto reads "The future is in the hands of those who explore - and fro mall the beauty they discover while crossing perpetually receding frontiers, they develop for nature and for Humankind an infinite force."