A brief review on major advances in heavy fermion physics is presented including the Ce metal phase diagram, the huge effective mass detected in CeAl₃, and the successive discoveries of unconventional superconductivity in CeCu₂Si₂ and three U based compounds, UBe₁₃, UPt₃ and URu₂Si₂. In order to track the origin of the huge effective mass, the case of intermediate valence compounds is discussed with emphasis on the differences between Yb and Ce materials. The formation of the effective mass is analyzed by two regular- and singular-part contributions. Examples are given for both, antiferromagnetic (CeRu₂Si₂ series) and ferromagnetic tricriticalities (UGe₂). Pressure and magnetic-field studies on the ferromagnetic superconductor URhGe illustrate the role of the singular effective mass enhancement on the superconducting pairing. The discovery of the Ce-115 material gives the opportunity to study deeply the interplay of antiferromagnetism and superconductivity. This is clearly demonstrated by field re-entrant AF inside the SC phase just below the superconducting upper critical field (H _c2) for CeCoIn₅ or on both sides of H_c2 within a restricted pressure window for CeRhIn₅. The present status of the search for the hidden-order parameter of URu₂Si₂ is given and we emphasize that it may correspond to a lattice unit-cell doubling which leads to a drastic change in the band structure and spin dynamics, with the possibility of competition between multipolar ordering and antiferromagnetism.