Regarding the debate over Captain America being an easily associated brand of Marvel, one might say that in current awareness of comic book fandom, however, longevity must be factored in. Cap was created in 1940 and was huge through the war. When he was brought back in the 60's he became the face of the Avengers and never lost popularity. I was reading these in the late 70's when the X-Men was just some obscure little book. Spidey, Hulk, Cap, Iron Man and Thor were all over lunch boxes and t-shirts. I remember my brother reaming me for embarrassing him when I went with my class to orientation in Middle school wearing a Marvel comics panel illustrated t-shirt.
FF has always dealt primarily with cosmic or other dimensional baddies, and to this day I think one of the greatest arcs they ever had was the Xandar/Sphinx/Galactus series with Byrne doing the art. Truly a definitive period in the history of the title. If "new" fans would go back and read these I think they would garner an appreciation for the classics.
I see it as a problem in our current 15 second attention span culture where no one cares for history, there is no reverence for classics and think that newer equals better. Sad.
He was also the first Marvel cinematic superhero, beating even Superman to the big screen by four years (and only one year behind Batman.) Though in the original 1944 serials Cap wasn't super-soldier Steve Rogers but rather Grant Gardner, district attorney turned vigilante.