you should look at either ASUS P5N series or the Gigabyte DS3. Hardly anybody on here is getting a different motherboard than those two.
I don't know much about the P5N series other than their more ram picky, can't oc as much as the DS3 but are more stable.
If you're on a budget of 1200-1400 and are going to be getting a good graphics card then get the DS3 otherwise you might want to look at the better P5N's.
Also the DS3 will let you overclock about as far as you want whereas the P5N's (from what i heard about a month ago) will only let you overclock a medium amount. (the general could only overclock his E6600 to 2.8Ghz on a P5N and i have my E6400 overclocked to 3.4Ghz on a DS3 with the same ram.)
if you're not going to overclock then it really doesn't matter between the two and i'd just get the DS3 as it's cheaper.