Great links … I was just about to ask … where do your people get the textures from …lol
Thank you everyone! This has made it much easier to find textures… 
I made a free prototype texture pack. Prototype textures like this are very helpful to measure the scale of textures, to see the distribution of textures during uv-mapping and to visualize an idea of an early level design of a prototype game. It can be especially helpful when you create your geometry in Blender. Also it can help to make game-levels from BSP/CSG geometry, where the mapping happens automatically.
More details can be found here:
Dexsoft-Games
bookmarked, thank you
Anything from Bittbox, of course!
Not many textures yet, but there are nice high quality high resolution textures including alpha maps 
www.leaftexture.com
One day, sunny, the air is fresh. A kitten with the rod and ready to go fishing.It went to the lake, and sat on the grass, waited for into the water, waiting quietly bait fish. Suddenly, the line shaking up, cat know, must be the bait fish.But, the kitten USES rod a lift, found himself caught is a wet Nike Air Max Shoes, mad. Took the Nike Air Max Shoes go toward ground top hit, still angrily to the Nike Air Max Shoes stared at. But a closer look kitten, found like something in the Nike Air Max Shoes twist. At this time, a small fish from the Nike Air Max Shoes jumps out. Kitten beaming, know oneself really caught a fish, delighted and began to dance together.Finally, little kittens with his own hands caught the small fish, happily returned home.
Good work…
I’ve got some old textures i enjoyed making here http://strange.ccs.pl/ feel free to redistribute.
Alister
Hey All!
I have spent years working with textures in 3D apps ranging from Maya and C4D, to creating textures for game design and virtual worlds like Second Life. I take a lot of reference images to make my textures from, as well as make use of the many free resources that can be found online.
I am posting my own Hi-Res images up for others to use as well. Free of charge of course. These are NOT ready-made textures, but the photo resources to make your own from.
Have a look at www(dot)grungetexturefor(dot)me and feel free to let me know if you have any trouble accessing the images. it’s all wide open, no accounts necessary.
Hopefully the admin won’t hate me for the side-step above. I am in no way trying to spam, simply trying to share a useful resource, and as I am always busy working, I don’t have the time to post here on a regular basis. If they check the link they will see. 
Also there is a Request-A-Texture box, so if you simply can’t find what you are looking for, let me know. I live in the heart of the city, and can walk out and take shots of whatever you need. Just as long as it falls within the theme of my site.
Cheers!
Hey guys, I hope this is OK to put here (didn’t think it merited its own thread). If you use GIMP and want to make easy tileable textures you can use this texture plugin: http://registry.gimp.org/node/25653
I’ve only been playing with it a few hours but the results are really good. If you’re a Windows Vista / 7 user the GIMP scripts folder is in \Users\yourusername.gimp-2.8\scripts not sure where it’s at on other installations. Just copy the .scm file there and you will have a Tileable option in Filters / Map / Tileable.
Good luck!
A lot of the links from the OP are dead. Could someone post a cleaned up version of the list?
Free high res planet textures.
All but one are using 360 Spherical UV mapping, with a single using Cross.
Thanks. Good work guys! But list doesn’t contain almost none references to free human textures.
I am looking for good FREE human textures, mainly facial textures.
I searched quite long time but I found only a lot of non-free textures except got3d.com (found here) and http://www.fineart.sk/ (contains very good stuff but small selection). Unfortunately there I didn’t found what I am looking for (facial hi-res textures). Does anyone know more references to free human high resolution images?
I wasn’t aware there are so many websites dedicated to textures, have been using only cgtextures since forever. Thanks.
I suggest also pakito-textures.org. I’m one of the mantainers. It’s young, but we hope to grow up quickly! Pakito-textures contains only creative commons textures. Hope you appreciate the news.
Don’t suppose anyone knows of a site that has good sci-fi based textures? 
mainly looking for console textures