These are the most popular HSF's for the conroes:
TT big typhoon
(there is a led version if you want led but its about $10 more for the led)
(make sure you use a fan with it)
there probably are a few more good ones but those are the most popular right now.
I think the ninja cools the best out of all of them. The zalman is the lightest, but im not sure about the sycthe and tt (i think they're about the same weight). Either way, if you use these, i wouldn't move your system around alot, b/c all of them exceed the specs for any mobo's weight restriction for cpu coolers.
For example, the zalman cnp9500 is 450g and the asus p5b-deluxe states no more then 200g(i think...its close i know that), so these hsfs are not meant to be moved around alot. But as long as you don't throw around your rig
, you should be fine with any of them.