The Italian ones are nice, as are the UK ones (if a bit cramped). The Nightjets mentioned in the article (mostly taken over from DB's CityNightLine a few years ago) are variable; the Poland-Ukraine one is pleasant enough but poorly timed. I had a pretty bad time on a Hungarian Railways one. The Russian Railways ones from Paris and Nice to Moscow have a reputation for luxurious looks but bad (or at least not westerner-friendly) food.