Well, at first I really didn't like Sasuke. In the beginning arc he seemed just too one dimensional, as did Sakura. Not only that, but he already had just about everything he needed, being the genius of his class and a person everyone talked about in "whispers" and such. I tend to favor the underdog, so I side with Naruto. I also like the clear growth Naruto is showing, whereas Sasuke's isn't so pronounced.
As the show has gone on Sakura and Sasuke have gotten better I think. They've at least expanded Sasuke's personality and motivation a little, even though I still don't think the core concept is very original. My only real gripes with him are:
He steals Kakashi away from Naruto a bit too much, and those two make a funny combination. Granted the author of Come Come Paradise was great too.
So far I've gotten a bit tired of Sasuke either saving everyone or easily overcoming a tough obstacle. I have a feeling many of the Sasuke fans feel the same way about Naruto almost always overcoming his obstacles as well, I think it's the same type of thing.
In general I'm not a big fan of the uber strong Ninja with a messed up past template, and we so far have Neji, Gaara, and Sasuke all filling that role.
Anyway, I don't really find anything about him appealing, but I don't really actively dislike the guy any more.
And I wouldn't call Naruto selfish. He craves attention because he's been lacking respect from others his whole life. He acts tough because if he doesn't the collective weight of his loneliness will crush him. Sasuke on the other hand wants no attention and will get the power that he wants even if it is at the expense of others. Fortunately Sasuke is moving away from that little by little, and becoming more easy to like.