I have been playing World of WarCraft for only about oh say 20 hours, and I already have a level 14 Warlock! The speed that you can level in this game really makes it more worthwhile to play. Its got a beautifully rendered world which the Blizzard servers have to keep up the whole time as there is no loading (except for the tram)!
The story of WoW basically goes like this, there are 8 races to chooses from, Orc, Tauren, Undead, Troll, Human, Night Elf, Dwarf, Gnome, and they are split into 2 groups, Alliance and Horde. This is where it gets cool, unlike most games wher its either PvP or its PvE this actually has both worked into the game very ingeniously. As long as you remain in your territory pretty much the only thing you have to worry about is mobs, unless the Horde decides to invade then you have to deal with them too! The races can get together and actually raid horde towns. If you win and actually take the town you kill all the NPCs in the town and they wont come back for a couple of days.
All in all I think Blizzard has a reall winner here. I give it a solid 10/10. This is a must have, if you can afford the monthly fee...