This isn't a question about which one you WANT to be next, but more a question as to which one you BELIEVE will be next. They've said they're working on another race, and there's generally a few nominal rules they follow in terms of whether a species is a valid candidate. Human-like features, nothing too outlandish. Generally no big horns or tentacles after the lekku problems with Twi'lek, but there may be exceptions. And enough desire to see them in the game.
So, with that aside, let's hear your thoughts. Offer just 1 choice. I personally am going to say the Nikto. They offer a close enough resemblance to human, with variations on a similar level to Sith Purebloods. They offer a good opportunity for variety in the appearance, tho we'd probably only see the variety with noses