Alright look, I'm sorry your favorite game that released last year or this year didn't enjoy huge mega success like GTA V did. Fallout 4 was a VERY huge game that released this year, but it WAS NOWHERE close to GTA V, GTA V had very much higer ratings, sells and so on. If Fallout can't do it, then which next game will? I know ITS NOT Call of Duty since each year the success of COD decreases(finally). Let me  remind you, I'm talking about games that sold really well and had super high ratings! Games such as Ocarina of Time, Super Mario Galaxy, GTA V, The Last of Us, San Andreas and other videos games that are CONSIDERED one of the greatest video games of all time (Such as being in the TOP 20). Rating at or higher than 95% and selling well over 7.5 million copies at least! Yeah sure Fallout 4, COD BO3, Destiny, Far Cry 4,  Majora's Mask 3D, Mario Kart 8, Super Mario 3D World, Pokemon X/Y were huge games  that released recently but didn't have the same success of the earlier games I mentioned. 

I know there's going to be alot of people out there who will criticize me for asking this, but I want to know! Comment your answers! What next game will be the next mega success video game?  

As of the current games we know of now, My predicion is that Zelda Wii U will be the next mega success game scoring just as high as OOT, GTA V, Last of Us, Super Mario Galaxy ect.  And will sell just as high as it's older sibling, Ocarina of Time.

Zelda
Zelda
Zelda
Zelda
Zelda
Hopefully MGS V

I think Uncharted 4 could be one of them if the story is done right, I have faith in the naughty dog team

Uncharted 4 based on your criteria.

Probably Uncharted 4.

Uncharted 4 has a really good chance of doing so, but if not I'm sure Zelda can do it if Uncharted doesn't, possibly even Final Fantasy XV if they get the game right.

GTA 5 was crummy.

There, that's all I wanted to say.

Uncharted 4 has a great shot. GTA VI will do it, of course! You think Zelda Wii-U will sell at least 7.5 million copies? Could be tough.

GTA V ain't even in the top 500

Uncharted 4 seems like the obvious answer but I doubt it will outdo Uncharted 2, which I would consider to be just on the outside fringe of the Top 20 games of all time. Btw I strongly disagree that GTAV is a Top 20 game, given that I was unable to even bring myself to finish it unlike every single one of it's predecessors. As the years go by, people will look less and less fondly on GTAV IMO. If you listened to people when GTAIV came out, they were telling you it was one of the greatest games ever made by GTAIV is a distant memory now for most, loved by very few. Based on the OP's criteria, I would say that Last of Us is the last Top 20 game to come out, which incidentally came out in the same year as GTAV.

It's a good question but I'm struggling to think of one. We may have to wait as long as whenever Red Dead Redemption 2 is announced. Maybe The Last Guardian? Maybe Persona 5? I doubt either of these despite writing them. There are so many great games coming out in the future but none of them looked like they will be phenomenal (and I mean that word in it's literal sense). Given that gaming is 30 years old and we have to predict a game to enter a small group of Top 20 in the near future, its hard because the near future doesn't have any games in it that seem like Top 20.