What is the best places to publish video games. I only know about amazon, steem, and itch.io
By far, Steam is the best place to publish PC games.
“What is the best place?” is the wrong question. What you should be asking is “How can I best reach my target audience?” Naturally, that requires knowing who your target audience is.
Once you know that, do some research to find out how they buy games, then put your games in those places. Steam is a likely culprit for many PC gamers, but depending on your audience might be missing the mark considerably.
“Best” depends on what criteria you are using. Steam for example has the most users, so it is “best” as far as install base. Steam is also a crowded market that makes it difficult for your game to be discovered on its own. Creating ads to promote your Steam game is difficult since players are rarely signed into Steam on their web browser and Valve has made doing so an annoying process. Players would normally need to open Steam and search for your game on their own before making a purchase, rather than doing so after following your ad link.