  We construct the pp-wave string associated with the Penrose limit of
$Y^{p,q}$ and $L^{p,q,r}$ families of Sasaki-Einstein geometries. We identify
in the dual quiver gauge theories the chiral and the non-chiral operators that
correspond to the ground state and the first excited states. We present an
explicit identification in a prototype model of $L^{1,7,3}$.
