In this chapter, the main results from the PIMC simulations of hot, dense hydrogen and deuterium will be discussed. We start with a brief study of the accuracy of the pair density matrix for the isolated hydrogen atom and molecule. Then we show results from many-particle simulations. Special emphasis is put on the comparison of variational and free particle nodes. The development of the VDM in chapter 3 (Militzer and Pollock, 2000a,b) and its application as nodal surface in PIMC simulations is one of the key points of this work. In this context, we discuss the high temperature phase diagram and study the effects of an improved nodal surface. We look at the pair correlation functions as well as the permutation probabilities of the electrons. Both will be used to review the predicted first order plasma phase transition by Magro et al. (1996). It will be shown that these results do change drastically if the VDM nodes are used instead of FP nodes. Following this discussion, we show results for densities and temperatures where the precise shape of the nodes is not important, discuss pressure and internal energy, and compare with results from other models and simulation methods. Finally, we give a detailed comparison with the laser shock wave experiments.