Well, time to say it again: The fact that the series is the masterpiece of the masterpieces.
When I played ssbm, there was one thing that amazed me so much that because of that, I started to love video games and play them frequently. Everyone who played ssbm or brawl need to watch on youtube by crappycapturedevice the series "history behind ssbm/ssbb". It explains where most of the elements came from other games and was translated and adapted to suit the ssb style. What blew my mind was seeing how detailed and how much toughs was put into this. Making a tribute to those genre of games that bring diversity to this industry in one single game is like a dream true. It's just taught me those genre and how to love them. Because I consider the game being the masterpiece itself, the best thing in smash for me is the game itself. It's the universal point between nintendro franchise that made our gaming experience different and memorable just like smash is.