You need to define worst. Do you mean the least financially stable, the most corrupt, or treats its customers badly.
I am a libertarian. I love capitalism, but I hate corporatism. Profits should be earned honestly, without relying on the government for bailouts.
So in my mind, JP Morgan is evil. And if what I heard is true about Bank of America being backed by the US government for all their dealings in derivatives, then they are evil too.
I do not know if your question has any relationship to Occupy Wall Street protests, but if it does we need to fix the underlying problem which is dishonest money. The federal reserve should not be allowed to print money unless it is backed by gold.