OnePlus 5T vs Samsung Galaxy S8
Both the phones have their pros and cons, I think you should go for OnePlus 5T. OnePlus 5T has the following advantages over Samsung Galaxy S8 -
1. OnePlus 5T has 6.01" Display Size while Galaxy S8 has 5.8" Display Size.
2. The Main camera of OnePlus 5T is 16 MP compared to 13 MP of Galaxy S8, though megapixel count is not a clear indication of a better camera, the more the better
It is not like that it is a one-sided game, Galaxy S8 has the following advantages -
1. The Weight of Galaxy S8 is 155 grams while the weight of OnePlus 5T is 162 grams.
Verdict - In my opinion, Nokia 6 is a better phone in overall performance but if you need a phone which is lightweight then you can go for Nokia 5 3GB RAM.
You can also compare these devices on 91mobiles. Link - OnePlus 5T vs Samsung Galaxy S8