GTA has reached essentially legendary status amid every game ever released, which is no small feat at all. GTA IV was a brilliant game for it's time but hasn't aged the best, so GTA V had a lot to live up to, but it did so so much better. The concept of having 3 playable main characters that you could switch between was almost revolutionary, but 100% genius. It made the game so much fun, and the little details, like being able to essentially customise your own play experience minus the main story missions ensured it is endlessly replayable, no single playthrough will ever be the same. The only downside is how cursed by time it's been. GTA IV had the benefit of 5 being released, adding a feel of nostalgia to it, but GTA V has been out for 10 years with no sequel, meaning everyone's done everything, there's not much else to do.