ABCya - Games and activities include: alphabetical order, upper-case and lower-case letters, counting numbers, connect the dots, numerical order, shapes, addition, e-storybooks and holiday games
KinderSite - Make sure you checkout the interactive stories.
Knowledge and Adventure - Content-based games and activities
Seusville - Interactive stories, games and activities from Dr. Seuss!
Clifford - Stories and activities from your favorite giant, red dog.
Starfall- A terrrific site for interactive reading and activities.
PBS Kids - A great resource of interactive items of all kinds.