no you're right, I was thinking of Camus. The lineage is Schopenhauer -> Nietzsche -> Heidegger -> Sartre, with Camus and Kierkegaarde by themselves.

Some criticism: Sartre isn't as respected as the others in academic philosophy (in popular culture, it's another story). Heidegger was an unrepentant Nazi who turned on his Jewish mentor after Hitler came to power, and Schopenhauer was considered a hypocrite by Bertrand Russell.

Nietzsche is clean, and pretty much practiced what he preached.

William Barrett, in his classic book on existentialism, Irrational Man, says that existentialism is the attempt to respond to the loss of universal religious faith in the modern era.