Jean-Paul Sartre's views on existentialism are brilliantly conveyed through his story of three strangers, put together in hell by fate. Written in French, I found Huis Clos to be one of the best plays I have read (or watched) in a long time. Sartre's brilliant use of symbols and rhetorical techniques nicely complements his theme of existentialism. An English version, No Exit, is also available but the beauty of the French language makes the original French version superior. If you are fluent in French, read it. If not, the English version will suffice.