vooshoos1. No longer human by Osamu Dazai
I love that Dazai book so much. I'd recommend going for the original translation personally because I think it captures the alienation really well through its obtuse language. The newer translation is known under the title "A Shameless Life" and I don't think it quite captures the mood of the original translation. However, due to the nature of translation, the newer release is no less valid than the former, and in some cases I'm sure it's a superior translation. That said, I still recommend the original, for the reasons posted above.
Once I know someone's reading habits a bit better, I generally try and recommend one of the following:
>Blood Meridian, by Cormac McCarthy
One of the most starkly beautiful and violent books I've read. Written in a somewhat obtuse manner, it's an extremely rewarding Western that follows The Kid through his encounters with various parties, all with a sense of inevitability and an acknowledgement of human brutality that can be shocking. Definitely worth a read.
>Roadside Picnic, by Boris and Arkady Strugatsky
The inspiration for the STALKER series and Tarkovsky film. A first hand account of pilfering a restricted zone and the adventures towards mythical treasure. Extremely vivid and features one of my favourite passages in fiction. The care and attention given to making their domestic situation feel real was fascinating to me, and I probably missed a lot of subtext too, given that it was written during the USSR and had to make it through the censors.
>Highrise, by J.G. Ballard
The slow decent towards a primal culture from within a contemporary tower block. This is a beautifully written novel and is also quite a simple read. I think that the novel handles the concept of societal breakdown much more effectively than the film, which plays more with visual and sexual decadence.
Also can recommend some of the following to a lesser degree:
>American Psycho, by Bret Easton Ellis
>L'étranger, by Albert Camus
>La Peste (The Plague), By Albert Camus
>Metamorphosis, by Franz Kafka
>Everything Is Illuminated, Johnathan Safran Foer
>Gaunt's Ghosts series, by Dan Abnett (bit of a guilty pleasure)
>Perdido Street Station, by China Miéville (flawed, but enjoyable)