I'm such a sucker for these kinds of discussion.

The usual answer is that it's whatever meaning you give it. Some people
prefer to let others do their thinking for them. Others think they have a
meaningful life when it involves harm to others. In general, it is the
product of activity and choices, rather than the accumulation of necessary
conditions. [AC Grayling]

But how then do we evaluate one life in the context of the choices of
others? And what does it say about the significance of death? A religious
framework adds transcendence, and escapes the myriad paths of narrow
self-interest. [Victoria Harrison]

Myth of Sisyphus by Camus suggests that asking whether life is worth living
is the fundamental question of philosophy, and everything else comes after.
A meaningful life is surely one that flourishes rather than fails. A life
can also have a dramatic narrative, where we are both actor and audience:
which also implies a finale. "Our heart is restless until it comes to rest
in you" said St Augustine. [John Haldane]

The universe itself has no obvious meaning, so how can we expect to find one
for ourselves? If we find a goal that gives meaning to our life, what value
does our life have once we have fulfilled it? Even if we assume God has
created a purpose for your life, it would mean something to God but not
necessarily to us. Is life worth living? Probably better than the
alternatives, and if you have to ask, then you haven't probably appreciated
them [Julian Baggini]

*From Sunday Herald*