Asus seems to be the best for Intel chips. I personally like GB's for AMD.
From what I see, Asus has the best out there for Sandybridge. SLI and Xfire compatible.
The trend seems to be x8 on dual usage of PCI-E slots.
But, right now, I don't think you can go bad with any of the name brand newer chipset boards, they've been out for awhile now.