Which debut console of the big three do you think was the best, and why?

Gameboy.

NES. Greatest console ever made.

Well... I like PS4/PS2> PS1.

Gamecube/Wii U/SNES/N64 > NES

But...

OG Xbox> 360>XB1

So I guess MS had the best debut console imo, but everything downhill since then.

I’m giving it to the NES. The NES got me into gaming in a big way and launched so many great series.

I also loved the PS1 for its then unprecedented RPG library. It was the closest thing Squaresoft ever had to having its own console.

Without NES there is no PS1 or Xbox. NES transformed the industry. PS1 helped evolve it but it needs NES to exist first. NES also gave one of the most influential games and most successful series of all time in Mario.

NES, no question.

Nes:
Teenage Mutant Ninja Turtles 1-3
Megaman 1-6
Snake Rattle n Roll
Super Mario Bro's games
Double Dragon 1-3
Battletoads
Chip n Dale - Rescue Rangers
Ninja Gaiden
Contra
Mike Tysons Punch Out


playstation 1:
Tenchu
Suikoden
Spyro
Vagarent story
Megaman 8->16, Megaman Legends 1+2
Street Fighter Alpha 3
Tomb Raider 1-5
Tony Hawks Pro Skater games
Metal Gear Solid
Twisted Metal
Legacy of Kain
Syphon Filter
Crash Bandicoot
Oddworld
Rayman
Gran Turismo
GTA
Grandia
Final Fantasy 4->9
Silent Hill
Resident Evil
Wipeout
Crono Cross (and trigger)
Xenogears
Legend of Mana
Wild Arms
The Legend of dragoon.
Parasite Eve
Medal of Honor
Final Fantasy Tactics
Dino Crisis
Persona 1+2
..

PS1 list with big name titles goes on and on.
Its debut was without a doubt bigger than the NES's.

NES was just the first. So in a historical sense, and what it ment for the industry its the biggest.
In terms of better games? the PS1.
(670-700 NES games vs 3100+ on the PS1, the NES had like 1-2 handfull of must own games, PS1 had much more)

"I think the best is.."

I think this question refers to the games? right.
Theres no question about the historical nature of the NES and its impact.
So the question is which had the better games?

Final Fantasy and all the wonderfull RPGs the PS1 had, def. makes it the winner.

Still the NES. 3/4 of the PS1 library has aged badly. 

You think the NES aged better? lol no.

I can honestly answear this way.
Theres very few NES games I'd want to go back and play (because must of them didnt age well).
Theres tons of RPGs on the PS1 still worth a playthrough, and even the "big name" IPs of multiplats that had their starts there, are still worth play throughs.