Depends on what you are trying to accomplish.
Personally, I just grabbed the abit IP35-Pro off Newegg for just under $150 (after MIR), but I really wanted the onboard firewire, e-sata, and RAID. Not to mention it's highly regarded in every review I read.
If you don't need all that, but want a serious overclocker, the Gigabyte GA-P35-DS3L is very popular, and just dropped from $100 to $90 at Newegg.
I've also been hearing some buzz about the MSI P35 Neo2-FR LGA 775, which is $100 after rebate.
That's just mobos I've researched lately, which is why the P35 bias. If you weren't going to overclock, you could go cheaper. If you knew you wanted Sli capability, that would be another direction altogether, etc.