Who Suffered The Most

We had a lot of great groups and bands in the sixties and seventies.  A few of these groups had their front men or women go solo when the group was at a high point in their career.  In most cases the groups had little or no success after the departure of their front man.  The Commodores , Kool & The Gang, Change, The Impressions, Rufus, L.T.D., Tower Of Power, New Birth and The Jacksons, were just a few of the groups that lost their lead singers. Which group do you think suffered the most after their front man left?