If Sasuke wasn't evil a major part of the show would be gone, but it would still be a good show. Honestly I'm surprised a lot of people aren't happy about that because they wouldn't have to watch Naruto endlessly chase Sasuke. Part one could've ended with Gaara losing the one tail and being saved by Konoha/brought back to life by Chiyo. It would've provided massive foreshadowing about the Akatsuki and would've spurred Naruto going to train and stay with Jiraiya for years.
Honestly right now the way the war is going, Sasuke's value is somewhat unclear because he really is no part of the war and I truly wonder how he'll be reinserted into the story.