I got a Scythe Mugen 2, it was not too expensive, gave some of the best cooling under load in a shootout somewhere in TomsHardware or google or something (lol) and was also pretty quiet. I got it because it was a good balance between performance, price and noise levels, with a slight lean towards performace. Im running my E6750 (stock 2.66GHz) at 3.56 GHz at lets say well over 1.5volts (about 1.54V under load) and it doesnt go over 62degrees C (47degrees max in CoreTemp) after playing crysis for ages, or running ORTHOS for an hour. So I'm pretty pleased with it.
I have a freind with a CoolerMaster V8 and it also looks cool, but it's massive and the included speed controller is not very good (comes out of the back of his case) and it makes a lot of noise.
I know the E6750 is a 775 CPU, but the Scythe Mugen 2 came with brackets for all sorts of sockets. Its also good because you can choose where to position the fan on the heat sink (as in top, bottom, left or right, and how far away from the mobo) so you have options when trying to fit everything into your case.
I got $30 off my Vigor Monsoon when I bought my 920 a couple of weeks ago.
(Or $30 off my 920 depending on how you look at it)
The installation was a bit of a hassle, but overall it's really a superb heatsink.
I don't know if I would recommend using the paste that comes with it though,
I always use good ol' trusty Artic Silver.