Frankly, my main concern in this whole conflict is religious minorities. I do not want religious minorities to be wiped out or slaughtered. I had hoped that overthrowing Assad early on would have given a better government to all of Syria and preserved the rights of religious minorities, but then many of the rebel forces radicalized, then ISIS happened and started slaughtering everyone who wasn't part of their specific apocalyptic creed of Wahhabism, so.... I guess I'm in favor of Assad? I might be in favor of Assad and his surviving brothers being arrested as some sort of palace coup, and possibly installing someone less vicious in charge, but that looks very unlikely as a possibility.
If Assad somehow "won" (which is impossible, assuming winning means regaining complete control of Syria, because the Syrian army at the very least lacks the capability to ever regain the territory controlled by the Kurds) there would 100% be a genocide of Sunnis... and the very process of Assad "winning" would be unbelievably bloody in the first place given the SAA's tactics so far (which largely consists of bombing things to rubble from a distance and hoping the enemy dies with the civilians, since the SAA is so unbelievably corrupt and incompetent they can basically never win a ground war even when they vastly outnumber their opponent and have vastly superior weaponry.)
The least bad faction is clearly the Kurds, but the Kurds also completely lack the capacity to come anywhere close to "winning" and don't even desire to gain anymore territory (their only gains outside of the territory they consider part of Kurdistan have been at the behest of their American backers, and they have a). limited capability to gain anymore b). no desire to gain anymore and c). with Trump's election America likely won't even be pressuring them to gain anymore.)
Nothing good will come out of this chaos. There is no major faction to "support" or "root for." Every major player in Syria is rotten now.
