There is a good comparizon given on the asus site.But in short
A7N8X-deluxe:upto 400 Mhz FSB,Sound storm/Dolby digital,Dual channel DDR upto 400MHz,Dual Lan,SATA,SATA Raid,Firewire,USB2,No IGP,OC friendly bios.
A7N8X-VM: FSB upto 333Mhz,Dual channel DDR 400 support,single lan,IGP,no dolby,USB2,no sata,no raid,no firewire,No overclocking.
A7N8X: FSB upto 400 Mhz,Dual channel DDR upto 400 Mhz,single lan,No IGP,No dolby,no firewire,no sata,no sata raid,USB2,OC friendly bios.
A7N8X-X:FSB support upto400 MHz, SINGLE channel DDR upto 400MHz,USB2,single lan,no IGP,no sata.no sata raid, no firewire,no dolby,OC friendly bios.