The just released Banker's global analysis of the top 1000 banks shows, by Tier 1 capital ICBC is the world biggest:

ICBC is also the largest by profits, assets, deposits and market capitalisation.

The banking story in 2012 was the Chinese banks out manoeuvring the US banks. They both have four banks in the top 10 with Citicorp slipping to 6th place. But in 1990 the Japanese banks also had six banks in the top 10 including the top three until their economic miracle collapsed. There are concerns for the Chinese economy, but not as great.

Europe is not a great place to be a bank with 9 out of the top 10 loss making banks are from Europe.