argh, u already mentioned the best coolers, eg the thermalright xp`s and the zalman 7700CU/b. :/
disadvantage about the xp-120 and 90 is that even if it fits on the mainboard it was hard for me to find a Case that it would fit in. Cuz due it size its often large then the mainboard and collidates with the psu if theres not enuff room between them. the problem occured o me with too many midi towers, so that my advice is to look for the size and the space between moterhboard and psu and see if it really fits b4 u buy one.
http://www.teschke.de/heatpipe...20-mainboard-kl-ss.jpg
furthermore watch ur hands when u apply the cooler, which is easy though but i lost a couple liters of blood since the xp-120`s edges are damn razersharp.
the zalman was even more easier to apply and wouldnt make any problems concerning size. I like the potentiometer alot and even when its running at full speed the sound is not loud though u can hear it but its not an annoying sound that comes from the cooler. good buy and cheaper then the xp-120 though i like the xp`s more when it comes to the design.