Best view by coach from Chengdu to Jiuzhaigou

Thank you Carl for your reply. I will be travelling by the west route (Chengdu-Dujiangyan-Wenchuan-Maoxian-Songpan-Chuanzhu Temple-Jiuzhaigou). However, am considering the using the east route out of Jiuzhaigou back to Chendu. To enjoy the scenic view, please share which side of the bus is the better option for both way.