Which game is da best on steam ? Recommandations please !

Sorry ppl can't help you in this.. we don't even know your taste in games how are we supossed to come up with an idea ?
Despite that if you're average player i would recommend PUBG
If you like pirate action you should go for Blackwake/Atlas
If you like building and sci-fi sometime some action go for Space Engineers
If you like surviving grinding etc. go for Rust
If you like slasher games go for DBDL
I could go on days like that ...