The Galaxy
The Star Trek universe is a big, big place, and every single canon world mentioned as being in either the Alpha or Beta quadrants in the first four series (TOS, TNG, DS9, and VOY), all the movies, and the first two seasons of ENT (no Delphic Expanse or Xindi, thank you) are presented in SFA, as well as other systems to help flesh out the territories of such obscure (but beloved) races as the Gorn, Tholians, Tamarians, and others. In total, the SFA galaxy is over 1200 star systems and nearly 1000 worlds or space stations to visit.