Just Grandma and Me was the first CD we happened to get for our not yet-2 y.o., who was of course too young to manipulate it. But we played with it together, and by "with" I mean it is not a game but a sort of enhanced flap book, where random object yield unexpected treats. The programs plays music, displays amusing animations, and so on. Most of all it's just simple fun, but also the most touching of the Just... series.
This is an easy choice as a straightforward and inexpensive title for younger children. Our 6 y.o. gets a kickk out of playing with it sometimes, though, and his 3 y.o. younger brother can manipulate it easily. A final note, I do wish this publisher and others had continued to include multilingual support -- here English, French, German, and in an earlier version Japanese -- and additional cost must be minimal, and it's really fun to hear the different renditions. If your first language is one of these "other" languages, you might prefer it for that reason as well.