Albert Camus still fascinates, on what would have been his 100th birthday, and more than 50 years after his premature death in a car crash in Burgundy (it's said that he was found with an unused train ticket in his pocket - he'd planned to go by rail to Paris to rejoin his wife and children, but had accepted at the last minute the offer of a lift from his publisher).
Unlike Sartre, who was more of a systematic philosopher, Camus preferred to be labelled only as a writer, since he was doubtful about the power of reason and preferred to focus on how one should live, especially whether one should be primarily "solitaire ou solidaire".
The great advocate of the former, isolated path is Meursault, anti-hero of L'Etranger (full text here), the first book I read for my French A Level course and one of the forces that launched me into adulthood. Meursault talks about the "benign indifference of the universe".
In Le Mythe de Sisyphe, which I studied for my MA course at Edinburgh, Camus offered "suicide, religion or acceptance" as three possible responses to the Absurd: he chose acceptance.
In late 2013, commentator Geoff Dyer said of Camus that he carried within him "an unconquerable summer" that still warms us today.
For more about Camus' life and work, I'd also recommend Albert Camus and The Absurd and a recent BBC series.