Wait. There's no way we've seen the intro yet. I saw something titled as such, but that can't be the intro.
If that is the one, it's probably my least favorite. Not because it's badly made, but everything is so disjointed. It's amazing for a direct where you are trying to hype something. Or maybe it's just not as powerful because it's just a piecing together of reveals I've been glued to along the way for so long. I love the visuals and all that they offer, I just like the old creative intros.
Brawls at least felt a little bit better paced and towards the end you were pretty excited to see the characters working together.
Melee's has the best visual transitions by far, the most connection with the music, and more interesting stand alone visuals rather than cut scenes from elsewhere pasted in. It's just a smoother ride that feels like it was made to be an intro to a game, instead of a bunch of cuts that work amazing in their own places, used further. It may not have the best graphics, but it wins for me. Plus it'll always hold a special spot; As I was growing up I got a group of people together online to make an animation collab as a tribute piece for it, each person picked a character and animated in their own style that fighter's transition/screen time. It sadly never saw full completion but the pieces we did make were amazing to me, and it branched into other fun projects. It was a great ride either way.
And finally... Melee has the announcer's exclamation at the end which is an automatic win since it's excluded from these last two (even if it started a million "mee-lee vs May-lay" arguments)
This is not just Melee bias, I currently enjoy playing smash 4 the most, but as far as the intro goes... Melee hands down if what I saw really was the Smash 4 opening cinematic.
The 64 version was fun and is a great intro to the series, but it is just slightly dated. I don't think it's fair to compare it tbh because it's not quite as good as Melee's but it's too different from 4 or Brawl. It has way more charm in some areas, and then some not so up with the times visuals. But it closes with the announcer so....
Edit: wow this is a lot for intros lol, but the game has always been huge to me, so it's not like it's hard to rant.