Same here to the T man. Good way to put it too, as I honestly never mention it to anyone as I don't want to disappoint them, but the series just has never grabbed me.
I tried 1, 2, 3, 4, and 5 for at least an hour each, and I tried 2, 4, and 5 on co-op as well just to see if that would take; didn't work.
I tried the multiplayer for 5, as I know a lot of people love the multiplayer for these games, and it wasn't my thing either despite me being admittedly weirdly good at it, which doesn't even make sense as I don't typically play online and I almost never play third person shooters, but I digress.
I wish I could figure out what it is that makes these games so legendary to so many, but I can't. They're definitely well made, that's an objective fact, but they just don't pull me in for some reason.