I think it depends on the individual and the amount of faith that they have. I have known many people from different religions. Some have been very ethical while others have not not been ethical. I really do not think that it is related to a specific religion but rather the faith that the individual carries within.
I think that if there is a conception of spirituality in any mode of relationship, there is ethical considerations. The idea of "most ethics" can be broadened to simply invoke "ethical conduct," and to the end, spirituality meets this understanding. The major challenge we have in our cultural and conditional context is being pluralistic enough to understand the ethical considerations that are in as many religions as possible and not relying on superficial and reductive methodologies to substitute for a true understanding of as many religions as possible. When we are able to engage in this reflexive exercise, we might have a chance of understanding better religious understanding and expression.
I believe you wish to discuss the extent to which different religion aim to promote ethical behavior among its followers.
In discussing this question meaning fully we must differentiate between the basic philosophy and teachings of any religion from the way it is actually practiced.
No major religion in the world is less ethical than other religion, as far as the basic principles of the religion are concerned, however in the name of religion, people from all religion have been committing atrocities that cannot be considered ethical by any stretch of imagination.
One of the major cause of such misuse of religion is the tendency among people to establish the superiority of their own chosen religion over others, rather than just practice the religion. Therefore, I suggest that we do not get into a debate here trying to discuss which religion is most ethical.
I believe my religion is the best for me, just as your religion is best for you.
It all depends on your definition of what qualifies as a religion, because many religious works are also didactic and with endless stories; it is really hard to say which has the most advice or tenets to follow. If I had to choose, I would choose the Bhagavad Gita because of its length and amount of teachings.