going_merry
The first ship of the Straw Hat Pirates that was so loved by its crew, it even developed a spirit Franky (one piece) described as a klabautermann.
Sadly, it had to be decommissioned after receiving extensive damage during the course of its service, which caused a severe conflict between its captain and Usopp, during which the latter was kicked off the crew, but was able to reconcile with him and rejoin.