I was thinking that some of the textures in tf2 don't look quite up to par... so i headed off to google, and low and behold there was an answer...
basically you have to change the mat_picmip value, from 1 (or whatever it was on) to -1 (as apparently any lower will get you kicked from servers - which is a shame, as the lowest value is -10 and looks pretty sharp)...
anyhow, here are some before/after shots... you can see that the texture isnt perfect at -1 but it certainly looks better than the default value:
Before:
After:
credit to these guys
so just shove
mat_picmip -1
into notepad, and save it as "autoexec.cfg" in this dir: C:\Program Files\Steam\steamapps\[your email here]\team fortress 2\tf\cfg
[e!] oh scratch that, looks like if you set your textures to "Very High" it sets the picmip value to -1 anyhow...