What are the best options for texture?
For best = simplest: don’t use it.
For best = prettiest: find a nice texture, then use it. 
I’m sorry, but it is impossible to answer your question because you give no background what you want to do. The “best” solution very much depends on how you measure what best is for your circumstances: do you want very high resolution, very large number of textures used at the same time, fast video streaming, etc.
i need the texture mapping is fast
That didn’t really help. You’re going to need to use more than a sentence to describe your problem.
What kinds of textures are slow? How do you know that textures are the cause of your performance problems? Are you using shaders? What shaders are you using? And so on.
well, i am developing a soft shadow algorithm based in this article: http://www.gamedev.net/reference/articles/article2193.asp,
I apply post-processing and then I copy the final texture on the screen.
this last step is the slower, up 20 fps, even without drawing anything, and this is just texture mapping, i tried by setting GL_NEAREST in texture parameters but this changes nothing
I tried by reducing the fbo width below 256 but this changes nothing, while the window is bigger, slower turns
see the screenshot: http://www.youtube.com/watch?v=ARKDOEmcAZ8
my guess is that the blurring process limits the whole thing, since changing fbo size changes nothing.
no, i tried by disabling the blur