I don't really have a suggestion for you (simply because there are so many decent ones out there) but the one thing i WILL recommend is getting one that doesn't use intels stock mounting mechanism. i've built 3 comps so far with the 775 socket, 2 with custom coolers, one with the stock. The stock one was horrible, you had to push down MAD HARD, so, the first time i didn't get it on all the way (i noticed by watching the temps go up), so i had to push it even harder for it to click in....and even then, it never made an audible clicking noise.....
I use a zalman 9700, but you might look into a zalman 9500.
it may be a little more than mide range though.