I was against him having such a prominent role in Super, but I did like his more serious demeanor during the Tournament of Power. Otherwise, I definitely liked his role in the Piccolo Daimao arc.
Yeah for a serious answer definitely his actions in the Piccolo Daimao arc. Roshi was more or less a comic relief character aside from his actions as Jackie Chun. I really liked seeing his demeanor shift when he realized what a serious situation they were in. Also his willingness to throw away his life won some points in my book.