Hokuto no Ken: Raoh Gaiden Ten no Haoh

These shows both have the same basic plot. Each show having the main characters fighting to rule the lands and having to gain allies along the way, having to show true "manliness" in a lot of the episodes. I'd rate, Souten Kouro being much better as it has more of intellectual aspect where as the, Raoh Gaiden series is more about winning with a punch in the face. 

In each show, one of the main characters is a conqueror who aims to rule the land, alongside their own group of warriors, who also get a fair share of the spotlight. The fights, strategies and betrayals that ensue have a similar vibe. Ten no Haoh has a focus on deadly martial arts styles, while Berserk's combat is more grounded, at least initially. Although the settings are different (one is set in medieval times and the other in a post-apocalyptic wasteland) they feel similar somehow. It should be noted that Ten no Haoh is best enjoyed if you're already familiar with the original Hokuto no Ken. read more 

Manly villainous rulers who want to unify the warring lands by using their fists. 

The "villain" in each series has a goal of creating their own empire by conquering the land and defeating those who stand in the way. Both series have a martial arts heavy plot and characters that believe in destiny. 

Both titles are set in a post-apocalyptic setting after the earth was destroyed by a devastating event. The main protagonist in both anime uses martial arts to kill anyone that stands in their way. They are also both action-packed anime with lots of blood and gore. The differences between the two is that Apocalypse Zero is more wacky and has mutants for enemies while Legends of the Dark King: A Fist of the North Star Story has humans for enemies and has a better plot. If you enjoy one, you should like the other as well. 

Both series features a lot of action and the main male protagonist is a strong character with his own ambitions. Both series has similar artwork and style with exaggerated comedy and violence. They both take action and presents it in an entertaining way that's more than the typical 'strategy/shounen' fights. Both series has a shounen vibe to them that has a old school feeling.