When it gets to the point when you're no longer mobile, can't SEE, can't maintain yourself on your own... then yeah, it's time to die.
I don't want anyone bathing me, cleaning me in the bathroom, feeding me all the time, since I can't do it myself. To me, that's not living, that's just 'staying alive', and for what? Just to set a record?
On the other hand, if I'm still mostly independent, then fine, I won't mind seeing 100 years old. Right now, though, I can't even imagine being that old. Can you? What would it feel like? Uuuugh.
My grandfather gave me some great advice:
"Don't ever get old".