They are all real close right now. The Epox is probably the value king with Nforce audio and Firewire, and great o/c options for around $83 shipped. The "top dog" right now, IMO, is the Abit NF7-S which adds digital audio out and S-ATA/RAID for about $115. The Asus A7N8X Deluxe is also popular, but a bit pricey @ ~$130 and not quite as good @ o/c'ing.
Also, some people seem to like the new Gigasuck board, but I can't suggest it. 😉 😛