1. Fight The Zombie Horde!
Mission: Michael, Trevor and Franklin wake up one day after a particularly heavy night celebrating a good heist to find that Los Santos has been taken over by flesh-eating zombies. Now, they only have one objective: get the hell out of Los Santos and find out what's going on. In one branch of the narrative however, Trevor carries on planning out one last big heist at the CDC that may just save everyone. Likelihood: Red Dead Redemption's Undead Nightmare is an ingenious piece of DLC that fuses Rockstar's Western world with that of brain-eating monsters. On paper, it shouldn't really have worked. It was released while zombies were everywhere (something that hasn't really gone away) and it didn't seem to fit well. But sometimes things surprise you, and Undead Nightmare was a revelation, not to mention great value for money. I'm just going to call it now, there is absolutely no way that zombies will appear in GTA V, outside of mods. Rockstar aren't ones for re-treading ground or making a quick cash grab. I imagine great things will come out of GTA V's inevitable DLC packs, but zombies are old hat.
Verdict: No. Just no. So there we have it. 5 missions that aren't going to be in GTA V. And as a bonus, here's:
The One Mission We Definitely Will See: Follow Mission
Goddamn it...