I've gone on about my love for Stannis a lot, but here's a few reasons why he's great from /u/TheAvenger1234

Oh gosh, I could go on a tirade about why Stannis would be an amazing King and why people like him, but I'll keep it short and use some quotes. I shall bring justice to Westeros. Every man shall reap what he has sown, from the highest lord to the lowest gutter rat. And some will lose more than the tips off their fingers, I promise you. They have made my kingdom bleed, and I do not forget that. Stannis views being King as a job, not a title or honor or anything less. Duty is the number one thing for him, that and justice. He does not play favorite, nor does he show mercy. Those who do good will be rewarded, and those who do bad will be punished. EVERY MAN WILL REAP WHAT HE HAS SOWN. I never asked for this crown. Gold is cold & heavy on the head but so long as I am the king, I have a duty … If I must sacrifice one child to the flames to save a million from the dark … Sacrifice … is never easy, Davos. Or it is no true sacrifice. Stannis commenting on Edric/Gendry. I am king. Wants do not enter into it. I have a duty to my daughter. To the realm. Even to Robert. He loved me but little, I know, yet he was my brother. The Lannister woman gave him horns and made a motley fool of him. She may have murdered him as well, as she murdered Jon Arryn and Ned Stark. For such crimes there must be justice. Starting with Cersei and her abominations. But only starting. I mean to scour that court clean. As Robert should have done after the Trident. Another example of duty coming before wants for Stannis. Lord Seaworth is a man of humble birth, but he reminded me of my duty, when all i could think of was my rights. I had the cart before the horse, Davos said. I was trying to win the throne to save the kingdom, when I should have been trying to save the kingdom to win the throne. THIS is the phrase that got me to really view Stannis as the Mannis. Dany wants the throne because she believes it is her birthright and whatever else Viserys drilled into her mind. Robb wants to be independent because his bannermen want to. Joffrey doesn't give two shits about Westeros. Renly wanted to be king because he thought he'd be a good one. Finally, Balon wanted to be a King to return to the old way. Notice a trend? They all don't take their title Protector of the Realm seriously. Stannis is one of the only people to realize that he needs to save the Kingdom before he can rule it, and he follows this principle. These pardoned lords would do well to reflect on that. Good men and true will fight for Joffrey, wrongly believing him the true king. A northman might even say the same of Robb Stark. But these lords who flocked to my brother’s banners knew him for a usurper. They turned their backs on their rightful king for no better reason than dreams of power and glory, and I have marked them for what they are. Pardoned them, yes. Forgiven. But not forgotten. Stannis isn't naive or foolish. He sees that there are true and loyal men and then there are sycophants, liars, greedy lords, etc. This statement is about the Lords he pardoned after Renly's death. tl;dr Stannis the Mannis is the only King who really takes his role seriously, follows the principles of justice and duty before all else, realizes the true threat is the others. Samwell Tarly states it best, "... one found Dragonstone, one found Stannis Baratheon, and a King who still cared." (Might be paraphrased)