Here is an interesting document (in french) from the S.E.L.L. with lots of graphics on 2018 sales for Console, PC and mobile gaming.
Edit for tldr (Thanks Konnichiwa and TheWPCTraveler :) )
Hardware down 2% but software up with 26%
Here's the top 20 games, then:
Note that limited edition releases of games are counted separately.
I assume this is what everyone is most interested in, on top of hardware sales for the consoles.
Top 20 2018 games sales by platform and by volume are Switch/PS4 mainly