Not to self-advertise, but I just finished my Simple Texture Pack. It has 100% custom terrain and 40% custom items. Custom Creepers and Zombies and even a custom Character. The entire GUI is custom too. You can change the character if you want though.
Here's the link to the download.
http://www.4shared.com/file/FH7sOAJH/AceCraft_V2.html
If you use it, please give some feedback for any changes that I should make. Thanks!
http://www.minecraftforum.net/viewtopic.php?f=1021&t=289773