Which research topics are most important for the future of humanity? In this symposium, a behavioral scientist, a philosopher, a computational cognitive scientist, and a former grant maker will discuss principles and methods for answering this crucial question. The symposium will comprise a series of three short talks followed by a panel discussion. In the first talk, Izzy Gainsburg will introduce the Importance-Tractability-Neglectedness framework for prioritizing research topics and illustrate how it can help behavioral scientists maximize their impact. In the second talk, Hayden Wilkinson will introduce the Expected Moral Value of Information framework for setting scientific priorities. In the third talk, Falk Lieder will propose a formal, computational method for estimating the cost-effectiveness of evaluation research and R&D projects in terms of how much social value they generate per dollar invested. Following the three presentations, Cecilia Tilli will moderate a panel discussion in which the three presenters will synthesize their ideas, discuss their implications for researchers, funders, advocates, and policy-makers, and outline future directions. Finally, we will leave the participants with a heuristic procedure they can apply to prioritize alternative research topics within their areas of interest or expertise.