That's the paradox of choice. https://en.wikipedia.org/wiki/The_Paradox_of_Choice
Since he's a younger person I'd stick to the 15 inch models. About 1300USD gets you a nice enough gamer. Don't think about 4K gaming. Let's go 1080p and maybe over 60Hz display.
Not that big on games? Drop to the 1050 Ti model for 700ishUSD.
PS. Due to the paradox of choice, there are many "best"'s.
I used to have a 17" MSi gaming laptop and I really, really liked it. Unfortunately I dropped it in the airport and it permanently damanged the video card. James (DaniWeb's sysadmin) uses it now as his travel machine.
What's your budget for the gaming laptop?
There are many companies in the market and trying to do their best in this gaming field. I would suggest you go with ASUS TUF series which is very famous for its name. ASUS has other gaming laptops also but TUF series is quietly affordable for every gamer.