Only GTA is possibility. ...

Even SA only did 20 million on PS2, and it sold 155 million consoles, so no.

With digital gaining more importance year after year, it will be impossible to achieve if we only count retail sales.

Unlikely, I would find it massively cool though if a Sony studio could catch lightning in a bottle like that and make a new game that becomes this successful (and yes I'm saying Sony, because I will likely only own a PS4 and I have no problem admitting that I like to see the PS brand do well :P)

GTA 5 have sold 19million on a 84million console. +  PS2 didn't really have any competition to take away it's GTA sales where as PS3 had Xbox360. 

PS4 will be something between the PS2 and PS3 in terms of competition so a late generation GTA could very well sell 30million on PS4.

Other then that the only possible way is if a game gets heavely bundled like Wii sports.

Only if the game was mass bundled for the whole generation or a very large portion of the generation.

The only game with a chance to do so is GTA VI, or possibly GTA VII.

Still, I strongly doubt it.

GTA V WILL sell 20 million on the ps3, and that will probably only sell 90 million max

That's because a considerably big factor of PS2's success in some regions was the fact that it was incredibly easy to hack. Here in Argentina, if you buy games legally you're called an idiot because you're "wasting money", for example. I can assure you I've met lots of people with GTA: SA in PS2, but none of them were legal copies. That's the reason why  SA had a smaller attach rate on PS2 than GTA V on PS3 while the latter has only achieved 53% of PS2's sales, at least in my opinion.

Not going to happen even if one consol reaches 100 mil sales. I's say 18 mil tops for the biggest selling game on a consl this gen