Depends on what you're doing. Programs like SAP2000 and ETABS have built-in design of steel and concrete, load combination options, and auto-lateral load generation based on design codes. Clearly better for design of steel and concrete. In addition, they have fairly extensive finite element analysis, dynamic analysis, and nonlinear analysis capabilities. However, in some areas, ETABS/SAP don't offer the analysis capabilities to the extent of an Ansys. For example, Ansys has more advanced material nonlinearity analysis options as well as the possibility of temperature dependent material properties. SAP/ETABS don't have the surface area meshing for mechanical design that you'll find in Ansys and Algor. But again, ETABS/SAP have useful floor/beam meshing and load distribution options that are not in Ansys or Algor. There is no best program for "every" type of structure.