The standard model of cosmology Lambda-CDM is widely held to be an excellent description of reality at large cosmological scales. However some fundamental issues remain: (i) The measured value of the cosmological constant Lambda looks unnatural from a quantum field perspective; (ii) The weakly interacting particles envisaged as candidates for the cold dark matter (CDM) are still undetected in the laboratory; (iii) The model Lambda-CDM falls short in explaining the observed regularities in the properties of DM halos around galaxies. The prevailing view regarding the issue (iii) is that it should be resolved once we understand the complicated baryonic processes that affect galaxy formation and evolution. However, this explanation is challenged by the fact that galactic data are in excellent agreement with the MOND (MOdified Newtonian Dynamics) empirical formula. In this talk we shall review the phenomenology of DM at galactic scales and discuss some alternatives to standard CDM, including modified gravity theories and hybrids containing some dark matter \`a la MOND.