A7N266-E. The A7N266 has no On-Board LAN, and uses C-Media Sound Chip, and has very poor overclocking. Whereas A7N266-E uses the nForce APU, has on-board LAN, and is maybe the best overclocking nForce/KT266A board avialable. I'd never get the A7N266. If you need something cheaper than A7N266-E, go pickup a MSi K7N420 Pro. Great board with LAN, nForce APU and is usually cheaper than A7N266-E, although it doesn't oc well at all.