I have looked through my Aliens sourcebook and remembered creating some never used SCs and some (used) NPCs from diverse Aliens from that sourcebook.
Amongst them were an Andorian and a Selay, as well as a few Romulan and Vulcan hybrids.
Have you used the stats given in the book to create SC/NPC aside from the species found in the PG? Unusual species, I mean.
If so, which species did you try and how happy were you with the outcome?