Minato - He's my favorite character, i believe that he's got allot more to show, and i believe he would be a great asset to the village, not only because he's incredible strong, but he's got a decent personality; would be great to see more of that.
White Fang - It was stated that he was a extremely powerful shinobi that was even equal or greater to the Sannin. I think it would be good for Kakashi to gain something, because from the beginning of the manga/anime, we've only seem him lose people.
Jiaiya - Naruto lost that little something special that Jiraiya brought to the series. I felt that he brought allot of emotion and funny moment to Naruto. I still don't think we got to see his full potential.
Kushina - I believe that it would be good for Naruto to have time with his mother, as mean... He is the savor after all. She should have the opportunity to see her sons achievements.
Nagato/ Konan - I believe that they two should be revived because, even though they are a massive part to the circle of hate, they have true intentions. I think that he managed to get ride of the weight that was burdening him, from being truly happy.
Konan just wanted to stick by her friend, and fulfill the wishing of her dieing lover. Thus, followed her only family she had (Nagato)
There are other people that would be a great asset and i would like to see back, although most of the people i believe have shown their potential and don't have much more to offer, people like.... Itachi, Muu, Third Hokage.