Clark Thames has recently upgraded his website (www.tutorialsforblender3d.com) to include a new game textures section. The textures are all free to download and most come with normal maps.
The textures are all from a texture pack made by Spiral Graphics, who used the Genetic texture maker and they can be used in both commercial and non commercial games. AllÂ the images are seamless 256x256 png (except for the skymaps which are 1024x1024)
The categories include:
Walls & Floor
Some example textures are shown below. Check out the texture page of the site here to browse the textures. Theres also a thread on Blenderartists.org for feedback and comments.