I will go with PS1.
1 - the strongest "first console" ever. In a market dominate by Sega and Nintendo, PS1 absolutely humiliated all the competition selling over 3:1 against N64. No console maker ever did such amazing "first console" and manage to penetrate such competitive market.
2 - First console to reach 100m units. It massively expanded the market and blow any possible sale expectations.







