There is no good general-purpose PDE solver, as there are all these considerations such as elliptic/parabolic/hyperbolic PDEs, accuracy/stability, FEM/FVM/FDM, linear/nonlinear, numerical oscillation, steady state/unsteady etc... But I do recommend FeniCS PDE solver [1]. It is fairly easy to use if you understand the finite element method and type of PDE you are solving for.

[1] https://fenicsproject.org/