Which is better, Sony or Samsung for an Android mobile phone?

In my point of view you should go for samsung 

1. You will get service even if the company stopped manufacturing of that phone where sony will ask you to change your device only.
2. Then you will get a bootloader it will help you if you are a developer which you won't have on sony
3. For new updates for your phone all you need is only phone but for sony you will need a pc too so basically you won't have FOTA update on sony

So basically samsung is better in terms of service but its not like that sony phone is bad it too have some good quality like sony phone have some good looks which you will miss on samsung 

In my point if I was asked to buy a new phone i will go for Xiaomi or Asus or Huawei or Motorola