Recently, Savage and Schuster studied inversion sequences (also known as Lehmer codes) and introduced their generalizations, called s-inversion sequences. They defined various statistics on s-inversion sequences and explored their connection with s-lecture hall polytopes. In this talk, we show that, for any sequence s, the s-Eulerian polynomial, namely the generating polynomial of the ascent statistic over all s-inversion sequences, has only real roots. This result is first shown to generalize many existing results about the real-rootedness of various Eulerian polynomials. It is then extended to several q-analogs. As a consequence we show for the first time that the MacMahon--Carlitz q-Eulerian polynomial has only real roots for positive real q. Similar results hold for the hyperoctahedral group B_n and the wreath product C_k \wr S_n confirming conjectures of Chow and Gessel and Chow and Mansour on the roots of q-analogs of the respective Eulerian polynomials. This is joint work with Carla Savage.