Final answer:
The former 'N Sync member who achieved a very successful solo career is Justin Timberlake. He's not only had hit albums but also extended his talents to acting.
Step-by-step explanation:
The member of ''N Sync' who went on to have a very successful solo career is Justin Timberlake. Justin Timberlake rose to prominence as a member of the boy band ''N Sync' in the late 1990s and early 2000s. After the group went on hiatus, Timberlake pursued a solo music career with hit albums like 'Justified' and 'FutureSex/LoveSounds', quickly establishing himself as a major force in the pop and R&B music scene. His success in entertainment extends beyond music to acting roles in film and television, making him one of the most recognizable and versatile performers of his generation.