What is more important, energy or entropy? What decides if something will change or remain the same? Energy or entropy considerations?
 A: If you are talking about the spontaneity of a process, then the enthalpy(not energy!) and entropy both are equally important. Actually, it is determined by the Gibbs free  energy which is a function of both, given by $\Delta G=\Delta H-T\Delta S$. The condition for spontaneity is that the Gibbs Free energy be negative. This can be shown as follows-
$\Delta S_{total}=\Delta S_{surr}+\Delta S_{sys}$
Also, $\Delta S_{surr}=\frac{q_{rev}}{T}=\frac{\Delta H_{surr}}{T}=\frac{-\Delta H_{sys}}{T}$ (By definition).
So $\Delta S_{total}=\Delta S_{sys} + (\frac{-\Delta H_{sys}}{T})$. rearranging,
$T\Delta S_{total}=T\Delta S_{sys}-\Delta H_{sys}$. For Spontaneity, $\Delta S_{total}>0$, hence
$T\Delta S-\Delta H>0$ or $-\Delta G>0$; giving
$\Delta G<0$ for a spontaneous process.
So, it actually depends on which OUTWEIGHS the other-energy or entropy-which decides the direction of the process.( Because maybe entropy has DECREASED, but if $\Delta H$ is negative enough to outweigh it and keep the Gibbs energy negative, the process is still spontaneous forward).
NOTE- My convention for the above calculation is- Heat absorbed by the system is +ve and released is -ve. Work done ON the system is positive and done BY the system is negative. You can choose your own convention and change the signs accordingly.
