It does all depend on budget.
As a medium strength modern gaming PC I would recommend as a basic idea :
Nvidia 1660 Super
16GB DDR4 RAM
500GB SSD drive and 2 or 4 TB hard drive ( or less depending on budget )
amd ryzen 3600 CPU
And a motherboard that is designed for that ryzen cpu ( doesn't need to be the best, maybe throw £80 odd at it )
Of course people are going to say that is not a medium strength build and suggest a £450+ graphics card is medium but it all depends on budget.
they all go outdated and have not caught up with 4K gaming yet anyway so I don't see the point.