If you passed on this title at launch, it is time to give it a second look.
The game revolves around a starship captain character of your creation. The extent to which you can customize your avatar is impressive. You will first play as a Starfleet Officer (Tactical, Engineer, or Scientist). Later you will unlock the ability to play as a Klingon. Throughout the game you pilot various "classes" of starships. You can use pieces of all the starships of that class to design your own ship model as well as pick color and design patterns. You also find, purchase, or win various pieces of equipment to customize the abilities or stats of your ship.
The game is split into two arenas: space and ground. Undoubtedly the space combat is the flagship feature. Your own abilities as Captain, the abilities of the Bridge Officers you recruit throughout the game and your ship build keep combat engaging. The graphics are all around excellent (for a mmorpg) and this especially shines while flying through space. Ground combat is not as exciting, although it serves the function of keeping space combat from becoming monotonous. It also gives you face time with the character you created as well as your Bridge Officers or fellow Captains and provides more customization for your ground equipment and abilities.
Being a Star Trek fan is not a requirement, although there is plenty of references and appearances by well known characters and plots. If you activley dislike Star Trek this is clearly not the game for you as it has a certain Star Trek "feel" to it. Although the majority are combat related, a few missions actually involve only going to a distant planet and scanning alien artifacts, or finding supplies for desperate colonists. This seems like a nod to the concept that most problems in the actual series were not solved with a phaser.
The biggest reason I will stick around and continue to play STO is the effort that Atari continues to put into releasing new free content and improving the gameplay experience. The forums are full of activity and monthly updates on content and patches. A mission modder tool will soon be release and while it will surely result in a flood of low quality fan fodder, I look forward to picking out the gems. In my experience fan mod communities (I'm looking at you Oblivion) can create content which surpasses that of most professional gaming companies.
Overall, if you have the time and a few dollars this game is worth giving a try.