I have Zalman cnps 7700-cu
and it's decent. Nothing amazing, but it's silent, easy to change rpm and it wasn't too expensive so I'm happy with it. Don't know if I'd really recommend this one, there are probably some better ones for the same amount of $$$.
If you can spend a few more bucks then http://www.newegg.com/Product/Produc...82E16835185027
would be a good idea. Though beware. It might cool well, it might look good. But the thing is HUUUUUGE
. Seriously, it's like the biggest damn heatsink I've ever seen. HUGE, you could probably kill people by just throwing that thing at them.
But other than the size it's a really great.