I wracked my brains for a suggestion, Mark, and it finally hit me......Jeff Smith's BONE.
An all-ages epic fantasy adventure, complete with cute creatures, daring adventure, unrequited love, heartbreak, laughs, scary monsters, and just about anything else you could think of. I believe it runs ten volumes, but they have a great omnibus that collects the whole thing for about thirty bucks. (It's MASSIVE, but younger readers don't seem to have any problems understanding it. I gave it to my daughter when she was 7 or 8, and she fell in love with it.)
Here's a link to B&N:http://www.barnesandnoble.com/w/4bone-jeff-smith/1107838311?ean=9781888963144
I thought of Bone, but thought it's for the 10+ crowd.