Ai wo Torimodose, the first Fist of the North Star opening song, is quite possibly the most hotblooded song ever made ("YOU WA SHOCK!! The sky falls with love!").
This version from the Raoh Den I movie comes very close to topping the original.
Not too mention Manga Entertainment's own version of their fairly short lived dub of the series here. This alongside their theme for StreetFighter II V.
A love song where the singer says he will EXPLODE HEADS WITH HIS FISTS... for love. Awwwwwe.
Let's not forget the music that plays whenever Kenshiro is about to kick ass! SENTOO! (which is sometimes mistaken as Ai wo Torimodose Instrumental, which it essentially is).
Just about every single opening song for Fist of the North Star qualify as Rated M for Manly. Here's the second opening used for the first anime, "Silent Survivor".
And here's the remake done by the same band that did the original.
Heart of Madness, the ending song of the 1986 Fist of the North Star movie, is by far one of the most awesome songs of the series.
Of course, this doesn't mean the remakes aren't full of awesome music. Check out "The Road of Lords", a song so manly that you'll feel a beard and chest hair growing out as you hear it.
That song was created and played by Tak Matsumoto, the guitarist of the most successful band in Japan, B'z. The guy has been considered by many to be a genius guitarist and the song certainly showed it. B'z itself would later sing the theme song to the 2007 Raoh Den movie, LONELY STARS, which is very awesome as well. Here's the live version [1]
The French opening needs a mention. It can't compete with YOU WA SHOCK, but it's still audible, quite upbeat, and manly as well. And this is an amazing achievement when we make a comparison with all the anime from that time who got a new, and in 99% of cases craptastic, opening.
Let's not forget the epicness of the first ending theme.
Kill The Fight, the theme of Fist of The North Star 2 by Masato Shimon anyone?
