Actor. Longer careers unless you are a top 5 legend musically.
Acting pays better to unless you are one of the legends.
An average actor can get work for 30 or 40 years with no downtime.
A singer is one bad CD away from being forgotten.
Actors have not had to deal with there material getting downloaded and copied illegally nearly as bad as singers.
It seems like people will always have the desire to go watch a movie on the big screen.
While those same people refuse to pay $15 for a CD anymore
Or you can take the "all of the above" route and become Justin Timberlake.
Actor. Longer careers unless you are a top 5 legend musically.
Acting pays better to unless you are one of the legends.
An average actor can get work for 30 or 40 years with no downtime.
A singer is one bad CD away from being forgotten.
Actors have not had to deal with there material getting downloaded and copied illegally nearly as bad as singers.
It seems like people will always have the desire to go watch a movie on the big screen.
While those same people refuse to pay $15 for a CD anymore
Singer, and it isn't even close. You did say "famous" --- so I'll assume money isn't a major concern.
Singers can drink whatever, smoke whatever, work (or not work) whenever. They can even molest children & teenagers, and nobody seems to care. Anything goes with the rock & roll lifestyle (for better or worse).