Wow...Just wow.
The gameplay, is a lot of fun. Being able to go around in raids and such is well worth the money. Although the PvP could be better, and because of this is nothing like Guild Wars PvP.
The sound is also superb. Its easy to tell when you are going to strike a critical hit after a while. Because of this, it gives your enemy(if you are in PvP)one last moment before they get hit really hard.
It does cost $40 to buy this game, which isn't bad considering the content. Add on top of that the MMO fee for the massive powerful servers, and you tacked on $15 a month. This may seem like a lot, but this game can keep you busy for many months on end.
Overall World of Warcraft is a great game, and you make a fine addition to any gamers' collection.