In my opinion, one of Rockstar's biggest mistakes was abandoning one of their most creative outlets - the radio stations consisting of Rockstar-created music. Most of GTA and GTA 2's songs were original, although some were just very little known. They did a very nice job with the songs they created. Two stations in III followed suit, Lips 106 and Head Radio. Some really good music on there. But they really shined their brightest on Liberty City Stories. They captured the vibe of the mid to late nineties so well. Lips 106 had the whole Backstreet Boys/NSYNC vibe, as seen here
And Head Radio had the whole nineties contemporary vibe down SOLID.
Why did they stop doing this? I know Head Radio was cut from IV, but it's anybody's guess whether it was original music or real music. I really hope GTA 6 gets one of these