I'm with the consensus here, UC4 has this battle on its pocket. Halo 5 lost to Splatoon with an userbase signifficantly bigger, so there's no way it's going to beat the biggest exclusive on the biggest userbase on the gen. Add to that we might see an Halo 6 on the XBone, while UC4 is probably the last Uncharted (was it? I've heard rumours about it, can someone confirm it?).