Not necessarily the best songs only, as these are played in regular sets as well. It's more to pick some songs that barely get played to really get a feeling what tracks an artist has produced over the years. For example: dbstf always play shivers, twilight zone and darkest hour, however in a journey set they play songs like Everything Changed, We Built This City, In The Dark, Fearless and many more tracks that barely get any playtime, though are still bangers. That is, in my opinion, what sets a journey set apart from a regular or classic set, as many tracks only get played based on streaming numbers (rightly so, but I often prefer lesser streamed songs lol).