Our kids have loved Reader Rabbit since they were two.  The Baby and Toddler program is engaging and educational and each year the programs get better.  What I particularly like is that they keep the balance between education and game way to the education side.  Just enough game to keep the math drills engaging and to encourage progress in spelling etc.  We currently own software through the second grade and my son would rather play it than watch TV.  I purchase our software at Amazon, but I have seen it in OfficeMax and similar stores.  We own the items below, but I would be confident to try any of their titles.