Very hard..
Normally I think i'd go for Uncharted 4 cause of Naughty Dog
But I think the coverage has made me pick Metal Gear Solid 5: The phantom pain
Though I feel like MGS5 may dissapoint, however it looks awesome
Also I only recently completed MGS 1,2,3 and 4 as well as peace walker and instantly became a fanboy, so there's that