I'm somewhat the opposite. I like Arrow a bit more than the others because of it's edginess and I always enjoyed the backstories in Oliver's life which gives context to his decision making in his current life.
I like both Supergirl and Flash in their own way also. I agree that Flash has kinda fallen off for me. I'm impatient though. They're spending too much time talking about the confrontation with Savitar. I'd rather them focus more on existing confrontations than them worrying constantly about something that is months away. They're stringing things out a bit too much imo.
Legends has actually grown on me a bit. I really didn't like it at first and thought it was entirely too cheesy. But I guess when talking about time travel, it's always gonna have a level of cheesiness. Once you embrace that, the show isn't half bad.