I did a couple alien species character models md5meshes:

[Stepan1010]

This one I got off Turbosquid (just the model - it wasn't rigged or textured):

 

This one I did the concept myself:

 

 

 

I'm going for a clean/simplistic aesthetic. Each species is going to have a color theme to help differentiate which kind of ship you are aboard. The top one is yellow/orange/brown/black. The bottom one is green/green-yellow/black - and their ships will have a good amount of grey I think as well (I must have been inspired by the Cardassians/Romulans for this one).

 

http://www.midwestvideogames.com/

[demagogue]

If Sliptip or John#s (or was it JohnD?) or people with their thinking get into TDM mapping, they might go for models like this. They've played around with scifi/fantasy hybrid FMs in T2, and I personally liked their detours.