Zalman VF900. Awsome fan. Its quiet and its amazing when it comes to cooling. I have my fan on 100% and i cant hear it at all. I got it around $35 on newegg, its $10 more for an LED fan (well when i bought mine about 3 months ago). But check out the zalman, you'll be happy with it.
btw i'm coolin a X1900XT and it idles about 40C and on load it gets to max 70C. Its also OCed to 690mhz core (from 620) and 750mhz mem. (from 720). I could go higher just to lazy to right now. So i hope that gives you a good idea of how the fan cools