If I say which one is good then I have to say android. Both platform is good but somewhere android takes advantage compare with windows.Basically people used phone to listening music, watch videos, etc.windows has no any good application to run videos.According to my experience moliplyer is only one good application for windows to run videos which is not free.But in case of android so many free application available in the playstore . But windows has a advantage that is there is no need to any antivirus which is a really big advantage.
In windows phone you have to download or install all application there is no scope to transfer application you have to download application.on the other hand in android you can able to transfer application through shearing application like xendar, shareit etc. so my personal experience android is more attractive and funful.