Existentialism: No News is Good News
If a philosopher or author calls themselves an existentialist, I think that's when you run. Most religious people seem to love Kierkegaard and most atheists seem to love Sartre. I feel like I'm going to be booted from polite society for saying this, but I hate them both, and not even with any kind of passion. I like some people who get called existentialists, but not ones who called themselves that, for example: Camus, Beckett, Kafka, Nietzsche. Those people are talented writers, and I think ideological existentialists would be nowhere if not for saying "I'm just like Kafka!" (Ideological absurdism just comes off as an edgy way of discussing uncertainty and misunderstandings, and seems never to have considered itself the same as Sartre's ideological existentialism.) However, they all managed not to give into despair, much less to preach the despair, insanity, and confusion to others, which now affects the entire world we live in, especially the most parochial backwater regions, contrary to what many people may expect. Oh, and Heidegger somehow seems fine despite Sartre using his work as the basis of his own awful proselytizing.