Speeder
The Speeder, one of the classic boats that have showed up in GTA 1 and the GTA III era, is a very good boat in terms of handling, speed, etc. It is the fastest boat in GTA III, and the third fastest on Vice City and San Andreas. It is one of the easiest boats to obtain, and can be found at many docks and ports throughout the cities.
In the original Grand Theft Auto, the Speeder is a car rather than a boat, and is one of the fastest in the game, but is susceptible to damage due to lack durability.