Both of of you need massive geek points deducted from this one.
The Smurfs definatly should have won of course, but nobody brought up the simple fact that the Na'vi are dependant on the planet for everything, they do very little themselves. As a society they pretty much bum off the ecosystem. They are powerful beings, but not because of anything they have really done. The Smurfs however use tools ranging from hammers and nails to wheelbarrels, to even occasional mechanical devices like tractors. What's more where the Na'vi are forced to appeal to the planet for anything special, the Smurf leadership... Papa Smurf, knows magic which is apparently his own power as opposed to something granted to him by a third party.
I mean if your going to have a nerdy discussion, at least do it right.
Now, the question of how Smurfs reproduce is a good one, however I'd guess that being inherantly magical that it's not sexually. Being based on fairy folk it's possible that
they grow out of the ground in flowers or something equally bizzare. On a disgusting level they might even reproduce asexually and when it's time produce their offspring by using their anus as a birth canal or whatever... assuming of course under their pants they even have human-like reproductive and waste expulsion organs, there could be something down there for the job like we've never seen before.
Of course the real reason geek points need to be deducted is because we're dealing with primitive societies of blue skinned aliens. I mean just off the top of my head a better competition would be the Chiss (Star Wars) against the Asari (Mass Effect). The Asari are popular in geek culture right now, and the Chiss have been popular since they were introduced... to the point where there was a (denied) demand for them as a player species in "Star Wars Galaxies" and they have been added into the upcoming "Old Republic Online".
At any rate, perhaps you guys will regain your nerd-cred, but it has taken a serious blow this week.