These are the aliens I have come up with so far.  More will be added, and not all of these will be important (some might never even be used), but, when I picture a crowded space port, these are the people I see.      

Tennelians: Physically they are tall and elegant in general.  They are humanoid, but have no nose or ears, instead possessing ridges with tiny slits.  Their skin is purple.  Their hair runs toward black or silver (in general). 

          They come from a planet called Seh’marin.  Members of the Empire (duh!)

          They are just, honest, and pretty much all that is good with the universe.

Brilli:  The Brilli have yellow and orange skin tones.  By human standards they are very lanky (meaning extremely slim and long limbed for their height).  They also have spots along the sides of their faces.  Their spots can be a variety of different colors and match their hair.  Their eyes come in only one shade – black. 

          Their planet is Brill. Members of the empire.  

          They are quiet and mysterious with incredible intelligence.

Reshi:  The Reshi are tall and grayish with soft membranes in place of ears.  They also have long and dangerous tails.  Most do not have hair, but those of a certain bloodline have long, straight, white hair.  They only have four fingers (well, three fingers and a thumb)

          The Reshi come from K’ram’nis.  They are not members of the empire.

          The Reshi are arrogant and cruel.  Their entire culture is based on slavery.  First they enslaved their own people and once they had reached the stars they enslaved others.  The first race they enslaved completely were the Dorrin, who had the misfortune of living on the planet immediately next to K’ram’nis.

Dorrin:  Bluish green with scale like patches where humans have eyebrows and scattered over their body.  They too run toward white hair, but some have green or black.  They have long, pointed ears that stick out from the sides of their heads.

          They come from Maharillia and are unfortunately enslaved to the Reshi.

          They are a quiet and respectful people, which allowed them to be easily overrun.

Selvaru:  These elegant people are tall, slim, and winged (like Koronue on YYH) with long pointed ears (think Hylian).  They are very humanoid.  They tend to like long hair.

          Their planet is called Sesshavenith and they are members of the empire.

          They are much like the Tennelians.

Navarish:  They are short and muscular with a wide torso and thick legs.  They have slitted, yellow eyes and no hair.  They appear villainous but are far from it.

          The Navarish also hail from Sesshavenith.  They are also members of the empire.

          The Navarish are gentle and intelligent beings, though they don’t look it.  They evolved on the same planet as the Selvaru and the two races are considered quite a rarity. On most planets one species destroys the others or enslaves them.  It is a testament to both species’ intellect and character that they get along so well.