A texture pack that not only looks simple, but has original sprite ideas, like TNT looks like a bomb, creepers are bombs that wear tuxedos, and cookies are doughnuts!
This texture pack can be used with randomobs too!

If you are using the newest snapshot, you'll have to
do a bit of labor (if you plan on using creative mode)
open the .zip folder, then open the "gui" folder and
delete the file "allitems" and then rename
"allitems_snapshot" to "allitems" so that the creative
inventory will look normal :)

But the Zombies and Pigmen are a bit bloody, so you may want to download Bugcraft Kids! for children.

Textures to complete:
Some Paintings
More MC 1.3 Textures?