once againg JAE is right.
keep in mind that RISA will cost you under 3000$ while ETABS can cost you over 7000$.
ETABS on the other hand is much more powerful and can handle very large structures, also can perform nonlinear dynamic analisis, pushover and can handle dampers on the analysis.
so as always, everything depens on your needs. If you are going to design small to midsize structures, then i think RISA is the choice, if you are going to design large or complex structures or need to perform advanced analysis, then you need a more powerful, and therefore more expensive software like ETABS, SAP2000.