Shit, I actually agree with dan.
Of course it is worth remembering that this whole thing kicked off with Assad violently suppressing peaceful protest.
A protest that began because he had a child tortured to death.
The remind is overwhelmingly responsible for the civilian casualties. It is the only dude that has bombed hospitals, shelled neighborhoods with heavy artillery, used tanks and machine guns against civilians neighborhoods, fired scud missiles at towns and cities.
The regimes attacks on the healthcare system have been particularly gruesome, resulting in many many preventable deaths.
I am sure that the rebels include some terrorist elements that have committed war crimes. However, not on the scale the regime has.