Sasuke:
1. Sasuke hasn't actually stated his intentions for the village. He has only said that he has heard about the mistakes of the previous hokages, but he hasn't stated how he would intend to "fix" them. Along with that, he doesn't necessarily share the dream that Madara and Hashirama had or the dream that his brother had.
2. Take a look back when he learned about Itachi's true past. He wanted to destroy the village even after learning of how much his brother wanted to protect it. Granted, he hated the village elders for putting his brother through all of that pain, but that isn't reason enough to want to destroy an entire village of innocent people.
3. Sasuke doesn't care what other people think about it. Itachi made it clear that the Hokage must be respected and acknowledged as a good leader and person BEFORE being chosen for the position. Nobody in the Alliance respects or likes Sasuke because he is an S-rank criminal who has acted without thought to others. The only exceptions to this would be Sakura and Naruto...and we all know the reason for them. What's worse is that Sasuke could care less about what people have to say. He doesn't want to listen to their opinions or advice. He always wants to go it alone, never wanting to let people in. Does that make for a good leader? Not in the least. Part of being a good leader is listening to what your comrades have to say. Having an open mind is very important, and Sasuke just doesn't have that. He doesn't even listen to his teammates for crying out loud.
4. He is easily influenced. I mean, come on, the guy has changed his resolve multiple times now. "I will kill my brother" to "I will destroy all of Konoha, starting with the elders" to "I will kill Madara Uchiha." And that's only a few of the times. Each time he was influenced by an outside force (i.e. someone telling him about the past). Only this last time did he actually decide to figure things out on his own and even then he was influenced by what Hashirama said. The Hokage should be someone who sticks to the path he walks. It shouldn't be someone who changes his mind every 5 minutes.
Naruto:
1. Naruto has always wanted to become Hokage. True, when he was younger he wanted to become Hokage so that he would be acknowledged and respected. Now that he is older though he wants to become Hokage so that he can protect the village and his friends.
2. Additionally, Naruto could have easily decided to hate everyone in his village. They all hated him and he never knew what love felt like until he met Iruka. That was at the age of 12. If he had wanted to, he could have blocked Iruka's kindness and could have embraced the Kyuubi's dark influence. He could have destroyed the village in no time, making them pay for all of the pain and suffering they put him through. To never have known love is a painful existence. It is a path with two possibilities- light and dark. Naruto chose to suppress the darkness inside of him and connect with others.
3. He has never deviated from his dreams or his nindo. Naruto has always been determined and gutsy. It's who he is. He never once said "oh well I'm tired of trying to have friends so I'll become evil instead." Nope. Instead, he pushed on and trained to become stronger. When he fought against the bad guys, he showed them his resolve and never went back on his word to protect someone. No matter how many times he was knocked down or demeaned, he got right back up again and showed who he truly was. Naruto constantly shows what it means to never waiver from a chosen path.
4. Not once has Naruto ever ignored what his friends had to say when it really counted. He cares what people think of him and he values their opinion. That's part of the reason why he tries so hard. Sure he is impulsive, but he does listen when it's something important.
5. Naruto wants to do nothing but bring peace to the world. He pushes himself to his limits in order to protect everyone. Self-sacrificing for the good of others- that is the mark of a good leader. Itachi did it, Minato did it, and Naruto continues to do it.
These are just a few of the reasons why I think Naruto would be the better choice for Hokage than Sasuke. But, to me, they are some of the most important ones. Oh, and if you are going to throw the fact that Naruto is still only a Genin, please remember that Sasuke is only a Genin too. He defected from Konoha after the Chunin exams were over and never tried again. He just has the additional disadvantage of being an S-rank criminal.