My kids both like the sugary, Yoplait yogurt, or (gasp) ODS likes Trix yogurt, but obviously that is not super healthy and protein packed. You can't make a kid like something. I don't like yogurt myself (except Yoplait Whips.)
I freeze puréed fruit in ice cube trays, and mix a fruit cube with plain, whole milk yogurt for DS. Some of his favorite fruit purées to mix with yogurt are plum, strawberry, blueberry, blackberry, raspberry, any berry + banana, cranberry and apple, etc.