(Note: any nForce4 board may have serious issues with certain models of Maxtor Diamondmax 10 and Diamondmax 11 SATA drives. Maxtor have updated the BIOS but downloading and installing it is a pain, and you have to back up your entire drive first. nVidia have not updated their BIOS yet.)
Whether you have Maxtor drives or not, it is well worth looking at the various ATI (Crossfire) boards. These are mostly passively cooled, and the northbridge and southbridge draw less power and run at lower temperatures than nForce4 equivalents: especially cool-running are the newest RD580 based boards which draw 8W apparently. (There are two main northbridge versions, the one-year-old RD480 and the new RD580. These can be paired with southbridges from ATI or from third party manufacturers.)
DFI RDX200 - the original RD480-based ATI board, troubled by a slow PCI bus so tends to have data transfer speeds 20%-30% slower than average for USB hard drives (including iPod etc), Firewire and Gigabit Ethernet, also some SATA bottlenecks (and no SATA II). On the other hand for general computing and gaming it is fast, and it is a feature-filled board with good audio, dual Gigabit ethernet, 8 SATA ports, and being a DFI board it is very flexible for overclocking or undervolting whichever you prefer. Actively cooled but quiet.
DFI CFX3200 - is the just-released RD580 replacement from DFI, seems to be very fully featured but no reviews yet.
Asus A8R32-MVP Deluxe - RD580 based, an excellent overclocker, CPU Vcore fully adjustable down to 0.800V, cool running passive northbridge and southbridge, fully-featured with dual GigE, 5 SATA ports and one external, good audio, Firewire and all other usual inputs and outputs. This has received excellent reviews. Only the CPU-fan socket is temperature controlled and the control of that is fairly basic, just two settings low and high. User reports on other forums indicate compatibility with Scythe Ninja.
Asus A8R-MVP - RD480 based, good overclocker or undervolter, single GigE and 4 SATA ports.
Comparative review of the Asus A8R-MVP and the DFI RDX200 boards, and a standard nForce4 board
MSI RD480 Neo2 - (already in the list) - a mid-priced ATI board, fewer features (only 1 Gig Ethernet), like others it has good audio and good overclocking potential, but like several other MSI boards it
appears to offer CPU overvolting only, no undervolting (can anyone confirm?)
Abit AT8 - (already in the list) - a well-laid out board with a passive heatpipe based cooler for the northbridge and southbridge, excellent fan control (see comments above), chosen by several SPCR members but ruled out for me because it omits a coaxial SPDIF socket - therefore useless for home theatre. Other SPCR members are using with a Scythe Ninja.
(I'm still researching if any of these boards are incompatible with large heatsinks such as Scythe Ninja or the Thermalright models - some passively cooled ATI boards
may have a problem due to the large size of the northbridge heatsink, but no problems with the Asus and Abit boards noted.)