A Starfleet class launched in the 2280s as a failed transwarp test, which went on to serve for nearly a century and included the Enterprise-B.
The Excelsior-class began with the USS Excelsior, a prototype built in the 2280s to test transwarp drive. The transwarp project failed, partly because Scotty sabotaged the Excelsior to keep it from stopping Kirk's crew as they took the Enterprise to the Genesis Planet. The design itself was sound, however, and Starfleet built a large number of ships of the class.
Hikaru Sulu took command of the Excelsior in the 2290s and helped Kirk's crew save the Khitomer peace conference. The USS Enterprise-B was a refitted Excelsior launched in 2293, and on its maiden voyage Kirk was lost to the Nexus. Many other Excelsior ships, such as the Lakota, Hood and Fearless, served well into the 24th century and during the Dominion War, often fitted with later upgrades.
The Excelsior-class is one of the longest-serving designs in Starfleet history, linking the age of the original crew to that of The Next Generation and Deep Space Nine. It shows how Starfleet values a solid design and keeps it in service for generations.