Hmm...well, here's a question for some fun!
If what Sakurai says is true, and we start out with only the original 8 on the roster...well, let's put the questions this way:
1) Who would you want to unlock first and why?
2) Would you want to do it the "streamlined" way, or go a potential alternate route and unlock them "Melee" style?
3) Would you want to do it all on your own or with friends along for the ride?
Personally, I always loved having to complete certain tasks to unlock certain characters back in the old days of Melee. Sometimes I've even thought about deleting my Melee data and going through the game all over again. Those days of Donkey Kong with his Down-B on 100 Man Melee to get Falco...those were the days!
If the game allows you to complete certain requirements to unlock certain characters, I think I might try to do it in order of when the characters were added. A lot of my favorites are in newer rosters (Greninja, Shulk, Ike, Snake) but because I feel like this could be my Smash for a long time and this series really means something to me, I'll unlock them in order if I can manage it. The nostalgia would be off the charts!
If I have to choose who to unlock first, and not in order, probably Snake, Cloud, Ike, and Shulk. Well, maybe Greninja too. But it would be weird having those guys and not Bowser for example.
The streamlining may be easier, but I think there's more value in it for me if there are other requirements to get them...like the 20 hours of Melee for Mewtwo!
I'm not sure about having my friends with me...like it'd be a ton of fun to hang with friends and take turns, but it's also like a personal thing for me. I've always unlocked everybody myself in Smash. Like if somebody was fighting somebody to unlock them, I would totally be like, "But I wanted to do that..."
It's the little kid in me I guess
!