From what's been brought up already, speaking only for the singleplayer experience, it's Titanfall 2>Infinite Warfare>Advanced Warfare.
As mentioned also, Black Ops 2 is a semi-futuristic setting and is one of the best whole packages for a CoD because the multiplayer is easily a top 3 for the franchise. The campaign is also excellent but for playing in 2021 it might be a little dated. If that doesn't bother you then I'd recommend that too.
Don't play Black Ops 3. It has one of my personal favourite multiplayer of the franchise but the campaign is completely lackluster.