In what way and why did Allah give special favours to Bani Israel?

According to Qur'an, Allah gave many special favours to Bani Israel. In what way did he favour them? What was the reason for this? How is different from the prophets he sent to the rest of mankind that we don't know the names of? Also, given the above, why would Muhammad (peace) not be sent to the people Allah had already given so much to given the importance of Muhammad above all prophets? (Here the Christian claims that Israel was specifically chosen and prepared for the saving work which could then after Jesus be spread to the rest of mankind who never received the call to God. What is Islamic response to this?)