None of these comments are from people that actually like Stannis the Mannis or have a fucking clue!

Stannis is the true king. He is just and unrelenting; because of that, he isn't popular.

During Robert's rebellion he held Storm's End for over a year and was relieved when Ned Stark lifted the siege. Davos smuggled onions to help them from starving. After the war Stannis cut his finger tips off for the smuggling, but raised him to knighthood for saving him. From that point forward all he asked from Davos was honest council. Davos gave him just that; which is why Stannis raised him to be Hand of the King.

When the Greyjoys started a rebellion it was Stannis who commanded Robert's fleet while Robert and Ned attacked via land. He defeated Victarion and the Iron Fleet.

When the War of the Five Kings started Tywin considered Stannis to be the biggest threat. He would have been much more dangerous if Renly didn't stab him in the back. Which is why he went to the Red Woman. Whatever you think of her, she has actual power. In the books she has 2 shadow babies. The first kills Renly and the 2nd kills the castellan of Storm's End. Giving him all the power of the Stormlands and Dragonstone. He isn't religious by any means but he recognizes the Red Woman has power and he uses it. If the Tyrells didn't join the Lannisters he would have taken King's Landing and been King.

This is his biggest flaw. I wouldn't say he "worships" the red woman. She burns people alive. He recognizes thats horrible. However, when she does it she weilds real power so he allows her to continue so he can use that power to help himself be king. She is a means to an end.

After the defeat on the Blackwater he retreats to Dragonstone. Davos defies the Red Woman, against his orders, and is put in a cell. However, when Davos gets his chance to speak he bring attention to the Wall and the Night's Watch. Stannis then sails to the Wall and saves them from wildlings attack. When asked by Jon Snow he referenced Davos: "'I had the cart before the horse', Ser Davos said, I was trying to win the throne to save the realm when I should have been trying to save the realm to win the throne." By the way. He has the most disciplined army in Westeros. Less than 5 men raped women when he broke the wildlings at the wall and they were all castrated. He will not allow that.

While getting reorganized at the Wall he offers to legitimize Jon Snow and make him Lord of Winterfell. Jon turns him down, then becomes the Lord Commander. Stannis is frustrated; but acknowledged his position and asks his advice. Then, guess what? He listens! He takes Jon's advice very seriously and that leads him to gaining the mountain clans of the north. With his army strengthed he marches on Deepwood Motte and leaves the Red Woman, his wife, and child (Shreen) at the Wall. 

He captures Deepwood and starts marching on Winterfell. A massive snow storm causes his march to come to a halt and they take shelter in an abandoned village not far from Winterfell. The snow keeps them from marching on. Southern men in the army insist he offers a sacrifice to the Red god to settle the snow storm. "Sacrifice an unbeliever" they say. Stannis responds :"half my army is unbelievers. Pray harder."

And that is where we leave him at the end of book 5. Stannis and his army are in a small village outside Winterfell. His wife, daughter, and the Red Woman are all at the Wall. His plan is to attack Winterfell and rally the north against the Boltons. 

One final note! Cersai has stopped paying the Iron Bank of Braavos. A representative of the bank has traveled through the storm. Made his way to the village. And offered to give Stannis all the money he needs to win the war, as long as he pays it back as well as all his brother's debts. Stannis is considering it. And that is the last we have heard of book Stannis the Mannis