The proton exchange membrane fuel cell (PEMFC) is a particularly promising energy conversion device for use in stationary or vehicular applications. PEMFCs provide high efficiency and power density, with zero emissions, low operating temperatures, quick start-up, and long lifetime. While the usage of PEMFCs has been on the increase, their commercialization has been hindered by technical issues such as water flooding in their cathodes. Flow field optimization is one approach to mitigating these issues, as the geometry of the flow channels within a PEMFC influences reactant transport, water management, and reactant utilization efficiency, and thus the final performance of a PEMFC system. This paper looks at some of the recent research that has been focused on modeling PEMFCs, exploring phenomena in them, and improving their performance, especially through flow field optimization. This paper shows how such modeling can provide useful information for PEMFC optimization, and, based on the research reviewed, presents recommendations that can be implemented in optimizing the design of a PEMFC bipolar for maximum performance. Among more traditional designs, the reviewed research shows that a serpentine flow field with small channel and rib size would perform the best at low operating voltages, and could be further improved by utilizing diverging channels with varying heights. Furthermore, additions such as baffles have been shown to improve the performance of various flow channel designs.