The Zalman coolers tend to be heavy but really cool well.
Tomshardware seems to like it:
just a note from the article:
A quick look at the game benchmarks indicates that any increase in processor cost, including money spent on cooling in the pursuit of top clock speed, would be better spent on a top graphics card. We used relatively low resolutions, and increasing quality only serves to put even more bias on graphics power. Yes, the lowly Core 2 Duo E6400 appears to be "good enough" at stock speed to match nicely with an upper-midrange graphics card.