What kind of Aliens would you like to see in future games?

Something different, you know without two legs, arms eyes. Something truly Alien, At least in the ME series they had the Hanar and Elcore.

Also it would be really great to be able to play as a Krogen or a Turean.

Gas, energy beings.  Heck the original Star Trek TV show back in the 60's, even with their awful special effects budget had some interesting aliens.  I remember there was one that looked like a rock and could tunnel through anything, the only way they could even talk with it was Spock had to do a mind meld. 

Won't happen, it would take two things that clearly Bioware lacks, imagination and the skill to be able to model it correctly in their current engine.  LMAO they can't even get human facial animations right and you want non standard life forms.  Good luck!

An alien species with three biological genders, having a different concept of sexual orientations. Also, many of them are gay.

Yes something like these, theres should be at least a couple, but majortiy will be humanoids because of the combat and skeleton, theres a reason you dont see hanar or elcor on the battlefields(hard to animate).

Getting to play as a Turian is like my wettest dream.

One of the requirements for me with the aliens is that they have to make at least some sense technologically.

technology is the refining and improvement of basic tools. Which means for a race to reach a technological stage it makes sense for them at some level to require the use of tools. The Leviathan from a very unique, if convoluted way, evolutionary abilities made sense. They needed servant races because of their lack of physical ability and thus relied on mental capacity.

The Hanar make sense, their tenticles could easily be used for tool manipulation. But that is where the Elcor confuse me (i need to go back and read their codex) they strike me as a 4 legged species, what use do they have for tools, and how would they use those tools? Thats where it falls short me me. When they develop new races I hope they consider that like they did with Leviathan. That is why it never surprises me that the majority of the species are human like tool users. Don't get me wrong, I am open to it as long as it makes sense.

Anything not asari.

Ninja Turtles.

As long as the alien comes with the sexy time, who cares what it looks like!

Sentient, organic, non-humanoid aliens.

Preferably a squad mate.

Hell, just put an Elcor and a Hanar on my crew.

I prefer a mix of humanoid and non humanoid. Maybe throw a cyborg race in there