My fondest WoW memory is questing in Elwynn frest for the first time with the peaceful serene background music.
It seemed like the zone was huge and mobs such as the Hogger were super epic, on top of this level 70's were amazing and the fact that they had pretty mounts and shiny gear made your jaw drop. (Not to mention their amazingly high hp pools)
The feeling I got when first playing WoW can never be recreated and I look back at it fondly.
Whats your favourite WoW memory?