Newegg.com is a good start, but with many of my friends with high end experience I'd say Azrock or Asus motherboards are very good I use both. Gigabyte is another good one, but remember to do your research on what devices, memory, VGA (Video CArd) and CPU the motherboard supports. Things Like Socket 775, ATA IDE, SATA, DDR2,DDR3 Intel Pentium D, Duo Core, Quad Core, and Extreme. When you search a board make sure the devices you have now are supported by the new MB. Newegg.com are good for giving the specs of the MB and reviews of the board. Good Luck!