What 3 launch games would make PS4 sales explode?

[Nem]

Gran Turismo 6 if it managed to look like a definite improvement...

Uncharted is meh... didnt seem to save the Vita.
MGS... isnt as huge as it used to be.

I would say that something like an exclusive Elder Scrolls or Mass Effect could make a difference. Remakes of Oblivion, FF7 or Mass effect 1 for example.

Also, an online MMO could give the network features a good push. SWTOR, WoW, GW2, TERA, PSO2... things along those lines.

It will all depend on the hardware itself to look appealing to customers. Its gonna be dificult if all we get is theoretical more power, like the Vita and the PS3 offered.
Sony should put more focus on the features that set the system apart like the free network play and/or beeing the hardcore machine for example (if thats what they are going for) or whatever inovating feature they bring that is actually useful and not a "backrub" that server little purpose. No one cares about a check list, we want to know what it is that we get with the PS4 that we wont get with other systems. Thats how you market product. Sony needs to learn or re-learn that.