I ALWAYS prefer sp games anymore. While it is sad that lately a lot of them release in crap condition, I find the writing is usually better. I played online YEARS ago when I was much younger, and it can be exiting for a while, but eventually you get burned out on the repetition, frenetic pace, cheating, and smack talk.
The exception being the ultra short campaigns that are included with online games like CoD. One standout that surprised me though was the very good and lengthy sp campaign included with Titanfall 2. I hope Titanfall 3 will be given as much sp love.