If you liked Charlotte's Web, I'd definitely give Stuart Little a go - that's one of my boys' favorites. Also...
- Little House on the Prairie books
- Pippi Longstocking (my kids seem to especially like Pippi Longstocking in the South Seas)
- Spiderwick Chronicles - this one is on the edge of appropriate - it is a little too scary, and deals with some pretty mature themes (divorce, difficult relationship with mother, a lot of fighting/mean behavior between siblings), but my kids LOVE the books.
- Magic Treehouse books (some parents really hate these books because the author is a bit loose with rules of grammar in some of the books, but I've found they are very easy for even my 3 year old to follow, and they keep the kids interest. They have just the right amount of suspense for little ones.)
- Right now at Target on the dollar shelves as you come in, they have some adapted classic chapter books. We picked up The Adventures of Doctor Doolitle, Peter Pan, The Wizard of Oz, The Secret Garden and several others. They are shortened and simplified from the original version. My children have been enjoying these a lot.
- We've also done adapted versions of Tom Sawyer and Huck Finn. We read these last fall before, during and after a trip to Hannibal, MO - the kids LOVED them. I hope they'll read the real versions in a few years when they are old enough for them.