I have spent most of my life living in or very close to Düsseldorf. Apparently it is not considered the worst place to live in ...
Quality of Living worldwide city rankings 2010 – Mercer survey
Europe has 16 cities amongst the world’s top 25 cities for quality of living. Vienna retains the highest ranking both for the region and globally and is again followed by Zurich (2), Geneva (3) and Düsseldorf (6). The lowest-ranking Western European cities are Leipzig (64) and Athens (75). In the UK, London is the highest-ranking city at 39, followed by newcomer to the list Aberdeen (53), Birmingham (55), Glasgow (57) and Belfast (63).
Levels of quality of living continue to improve in Eastern Europe, with most index scores increasing slightly. Prague is the highest-ranking city at 70 and its index score increased from 93.9 to 94.8 in 2010. Budapest follows in position 73 and Ljubljana in 77.
In the eco-city index, Nordic cities fare particularly well with Helsinki (3) the highest-ranked in the region, followed by Copenhagen (8) and Oslo in joint ninth place with Stockholm. “Nordic cities do particularly well because the modern parts of most of them have been designed with potential environmental impacts in mind,” said Mr Parakatil. Aberdeen (19) is the highest-ranking UK eco-city, followed by Belfast (30), Glasgow (47), London (63) and Birmingham (64).
Also see this post on Düsseldorf and some "Düsseldorf companies" (the best known of those might be Vodafone, hehe ...) and this one.