This list includes the ships that are actively being produced for normal service at the likes of Utopia Planitia. Some of these are modern refits of older vessels. If you're writing a newer ship then go for one of these instead of its older model - the same goes in reverse for if you need a ship that existed a while ago. For example, if you were writing a ship that existed in 2412, you would replace a Miranda-class with a Reliant-class.
Please note that some classes may be missing - it depends on the availability of being able to obtain a screenshot of them in-game.
Escorts are the smallest and most maneuverable of Starfleet crafts; tactical-based and equipped with canons, they are designed to swiftly disable enemy vessels while avoiding damage themselves.
Destroyers and Warships serve a mid-point between escorts and cruisers in terms of maneuverability and survivability. They are tactically focused and are used for laying down heavy fire in battle.
Cruisers are the workhorses of the fleet and are capable of filling a multitude of roles depending on their configuration. Although slow they have advanced warp cores and can withstand large amounts of damage, can extend their shields to support allies, and also have large cargo bays.
Science vessels are the most versatile ship found on the front lines of combat, able to be reconfigured to support other ships in different ways. They are the leading ships in scientific research and application. They may not be the most powerful or sturdy, but they can still be formidable vessels.