In terms of picture books for DS, my current favourite is Diary of a Wombat. He's loving Rudie Nudie, the Gruffalo, any thing with animal noises as part of the story, Spot, and Hairy Maclary. I've got a wonderful poetry book for DS, too (can't remember what it is called off the top of my head). It's got a huge variety of poems, and he seems to like to listen to me read them as he plays.
For older kids (maybe up to early teens), I've got the Rangers Apprentice Series, Harry Potter (of course), have heard the Percy Jackson series is wonderful, and as a kid loved all books by Tamora Pierce.
I love books!