In my opinion the two organizations making the most direct impact today are the World Food Programme (run by the United Nations, providing food to areas stricken by famine and war etc. https://www.wfp.org ) and Doctors Without Borders (aka MSF providing medical care to those most in need https://www.doctorswithoutborders.org ). There are a variety of water charities doing good work also. What's more immediately important than water, food, and health care?