OK I've gotta weigh in on this one.
First, the Filet O'Fish was my first beloved McD's sandwich when I was a kid in short pants and not equipped to deal with the ground beef.
That said, in kindergarten, my grade school was right next to a McD's and on the last day of school our twentysomething female lady teachers ordered McD's for everybody in the class, so that was my first introduction to the hamburger. (Except for the girl whose mom was on the Historical/Hysterical Commission and had opposed the construction of the McD's in the first place. She looked like the saddest person in the room. I hated her mother at age 6 for that.)
Since then, my opinion of McD's has gone way down. However, of all of their options, I think the Filet O' Fish is one of the most consistent. I wouldn't want to eat that every day, but maybe once or twice a month?
While we're talking burgers: In-n-Out, Five Guys and even Del Taco are the best options these days.
And I do hate the Filet O'Fish commercial.