About 900 refugees in Germany were given a survey (some of these were multiple choice).
52% said that they would only go back once Assad is removed (2nd only to 68% saying the war has to stop; 44% said ISIS had to leave the country). 58% thought more Syrians would stay in Syria if a NFZ was enforced to protect them from the regime's barrel bombs & aerial attacks. 79% said the Syrian authorities and their lethal military response to demonstrations are what led to the what is happening in Syria today, 70% said Assad and allied groups were responsible for the fighting (followed by 32% saying it was ISIS), and 73% said barrel bombs were a threat to their personal safety. So basically....
Assad/regime is the bigger culprit to them (and his removal is essential to the majority of the refugees in order to go back).
Only 8% of those surveyed said they don't want to go back to Syria.
What Refugees Think
....yet Assad is the lesser of two evils?
Putin says he's only fighting ISIS in Syria. Buuuut....
Only One in Five Russian Strikes in Syria Target ISIS, Analysis Shows
"Almost 80 percent of Russia's declared targets in Syria have been in areas not held by Islamic State, a Reuters analysis of Russian Defense Ministry data shows, undermining Moscow's assertions that its aim is to defeat the group...The majority of strikes, according to the analysis, have instead been in areas held by other groups opposed to Syrian President Bashar Assad."
""If you look at the map, you can easily understand that they are not fighting Islamic State but other opposition groups," said Alexander Golts, a Moscow-based defense columnist and deputy editor of online newspaper Yezhednevny Zhurnal."
So you should definitely back the rebels and/or the Kurds since they're the ones fighting against ISIS the most (with the rebels also fighting the regime).