Mon Cal, Quarren, Selkath, or Nautolan (something aquatic!)
Bothan, Rodian, Cerean, Wookie
I suppose they want to stick to humanoid-type species that can speak basic for the cut-scenes. But if my character spoke in alien gibberish and I had to read subtitles, I would be OK with that!
Bothan and Mon Cal would be my #1 and #2 wishes.