Any shuffle algorithm is fine but the problem is Spotify's brainlessness: it routinely plays songs it just played. If you are any long-term user then you have playlists of hundreds of songs and my guess is that you haven't heard some of those songs in ages which means ... the FEATURE IS BROKEN.
I'd prefer a weighted shuffle based on the staleness of a song in a playlist. That way you eventually get through all of the music but in a pseudo-random order.
I'd prefer a weighted shuffle based on the staleness of a song in a playlist. That way you eventually get through all of the music but in a pseudo-random order.