I'm leaning a lot toward Asus now-a-days, i have a basic P48SX-X in this rig ATM and have found it runs a lot smoother than the MSI 845E MAX2 BLR. Gigabyte are my next choice- i never EVER had a problem with a Gigabyte board- plug 'em in and set the BIOS, thats all you need to do
As for socket A, i have fitted quite a few Asus A7N8X-E Deluxe's- nice and easy to set up and the sound is pretty good quality. Another good choice is the Gigabyte GA-7N400 Pro2, totally feature packed with dual BIOS in case of flashing problems :P