I'm going to go against everyone here and say that Sasuke does respect Naruto. He is the only living shinobi that he sees as an equal and this is why he also despises him so deeply. Not to bash on Sasuke but he is the character with the biggest ego in the whole manga and another shinobi that is as good or better than him drives this superiority complex to the roof.
Think about it, he is born within one of the most notorious clan to every live, he is the son of the village's police force, his older brother is hailed as a genius and to top it off the kid is at the top rank of his class being praised as a virtuoso himself since he got old enough to hold a goddamn kunai.
Then comes Naruto, the class' good last, real freakin goof that is pretty much as sharp as a beach ball ( no hate, Naruto is just awesome this way) and they start to work together just to see that stupid mofo growing stronger and at a faster rate than Sasuke could not even imagine in his most wicked dreams. What do you think happens to the most egoistical person in that universe ?!
So in short, someone like Sasuke admitting someone as strong or stronger than he is, is respect. He even respected Naruto's wishes not to kill anyone from Konoha before they fight and ultimately he accepted to take Itachi's eyes so he can crush Naruto with all his might.
I honestly think that Naruto is actually the only person in the manga ( that is alive of course) that Sasuke acknowledges and respect. Enough to want to give all he that he's got into the fight he promised him.