The only COD games I've played are Modern Warfare, World At War, Black Ops and Ghosts. Ghosts is the only one I still own though.
It's the only CoD I've actually looked forward to playing. I mean I enjoyed playing through the campaigns of a couple of CoDs but this actually looked exciting to me.
I wasn't sure about Infinite Warfare due to the theme/setting, but it's getting more and more interesting each time I play. I also like that it's not completely linear. You get to choose which missions to do first.
It's a little more sandboxy which is cool.