Never seen the fuss with Spotify. I'd rather have my music actually on me and not mostly reliant on having Internet connectivity.
You have music on you in offline mode

. With spotify I look up a song, add it in my playlist, ad it's auto synced to my phone next time I'm online with my phone. No wasting time plugging in the phone to my pc or downloading crap from torrents or beemp3, or ripping a bloody cd ( bah I hate cd's). All a big bloody waste of time, this takes 2 seconds of effort and I have the song I like always with me.
You are only reliant on the Internet when looking for new things, my main playlists are all offline playlists, add a new song I like and It's always available even when internet is down. You have the music on you, 9 out of 10 times I use spotify in offline mode on my phone. Only go online once per week or so to sync new tracks on it ( and syncing requires no effort, just start spotify on your phone in online mode and sit back, even with songs not actually on spotify but only on your pc, it will sync mp3's in your playlist too automatically).
Finally, all my playlists on PC are offline playslist, if my router **** itself once in a while and I happen to be without internet for 10 minutes ( which is rare anyhow, who is without inetrnet these days ?) I can still play all my music.
The only situations in this day of age I can think off where you are with no Internet is:
You are in a rural/backwards area with no decent 3g cover or you are underground in a metro/train.
You can't pay your internet bill.
Technical errors, like a broken router.
I hope optical media dies asap, it's slow inconvenient, overpriced, and unnecessary, you can get internet connections far quicker than your average cd or dvd player.
/edit drunken rant about optical media over