A key component of characterizing multi-planet exosystems is testing the orbital stability based on the observed properties. Such characterization not only tests the validity of how observations are interpreted but can also place additional constraints upon the properties of the detected planets. In this talk I will describe my recent work on investigating the dynamical stability of various planetary systems, most particularly those with planets that lie within the Habitable Zone. I will show the results of studying four systems with extreme eccentricities in which the two known planets exchange angular momentum through secular oscillations of their eccentricities. I will further discuss the orbital architectures for two systems, HD 5319 and HD 7924, that show signs of close planetary encounters for which the scenario of coplanar orbits results in their rapid destabilization. An exhaustive scan of parameter space via dynamical simulations reveals specific mutual inclinations between the two outer planets in each system that allow for stable configurations over long timescales. I will present the results of dynamical simulations that constrain the location of additional terrestrial planets in the Habitable Zone of the Kepler-68 and Proxima Centauri systems. Finally, I will discuss the dynamical stability of the Wolf 1061 system and the potential impact of the evolving eccentricity of the Habitable Zone planet on surface conditions.