Well...there are lots of 'good' overclocking boards out there...DFI is the best.
Epox, MSI, Asus, Abit all make boards that are capable of hitting very high oc's...I only know the nforce 4 series well, so that's what i'm talking about. Epox has almost as many settings on their high end boards as the DFI...Which of course gives you more options for overclocking (but also makes it harder to oc, since you have less people oc'ing with them::ie less of a crowd to ask questions to...). Epox, MSI, Asus, ABIT have all recorded 300+ fsb speeds on some of their high end boards...
The Asus a8n-sli deluxe sucks for oc'ing stay away.
The asus a8n-sli premium is great for oc'ing until you hit 1.5vcore, where it doesn't allow a higher voltage. Rock solid however.
I don't have personal working knowledge of any other boards (in that name brand list...). But i've read up on several, as can you.
Non-DFI Boards that are interesting to me are:
Abit ABIT AN8 32X as well as AN8 SLI
Epox EP-9NPAJ NF4 (non-sli) and EPoX EP-9NPA+ SLi
Asus A8N32-SLI Deluxe
MSI K8N Diamond