Here at the New School Permaculture we use Triodos Bank
The main reason we use it is since its the most ethical and most user friendly we have found.
Triodos is a bank that doesnt makes investments on weapons industry and for us that is more than enouth reason to be using it.
Triodos bank its not perfect, after all it is still a bank but it is the best we have found until now that can be used in any country and context compared with the other comercial banks everyone is using it makes us feel (a bit) more responsible.
The best options for ethical banks are FIARE and JAK but we havent found them as easy to use as triodos...yet ;)
http://bancasininteres.blogspot.com.es/ (Banca JAK)
Here are some articles about the things that can be improved at Triodos
Articles in spanish