Some points from a spanish who has moved to live/work in the UK, and know working temporarely in Brazil...
- Location, close to main european cities, well connected to US, Asia,...
- Low cost flights to almost everyplace in Europe (at least from London).
- Finance / IT jobs, as far as I know some of the best career oportunities are in London.
- Working ours, agree, better quality of live in terms of working ours that spain or brazil, and better pay.
- The weather in summer, yes, at least if you have to work in a suit and tie.
- Public services, national health system,
- The pubs, sport bars, good atmosphere,...
- The races at Chester on ladies day.
- Nice places to visit, lake district, dover, bristol, the north-east coast,...
- Good indian and thai food avalaible, and some british (shepherds pie, fish,...)
- Notting hill carnival.
- Decent football league.
- TV, many quality programs, bbc,...and great sport coverage
- Women (?)