“Questing.”
While Frodo Baggins had one major quest, destroy The Ring, I’ve found myself in a cesspool of incomplete quests, filling my quest book to the brim with worldwide travels. From coast to coast, island to island and across the open seas I’ve got missions to complete with no end in sight.
It’s an addiction, a fascination, an uncontrollable urge to click any creature with an exclamation upon his head. I cannot stop taking on the responsibilities of the world all upon my lonely shoulders. Unfortunately, travel time is not free and I find myself traveling the world in search for quest “turn-ins” and random item drops from creatures small and tall.
When does it end? I turn in a quest to get another! A few quests have me traveling to far off lands where more villages scream for my help with yellow “!” above their heads. I must help a wandering soldier, a fisherman, a poor villager and the beggar; I do it all “for the horde.”
You can have something like 20 quests in your log at a time, I’ve got it full with quests from each land. Perhaps someday I’ll complete them all or throw them away to pickup others, realizing the value of each quest will decline as my character levels.
The lesson here, stay where you are until the quests in that land have all been exhausted. Ah, the trials of a wondering adventurer striving to conquer the land.
Many folks know the name Peggle as an addictive 
Microsoft has proven the achievement system is one of the best ways to add replay value to a title and inspire players to overachieve in every game title, no matter how obscure. Now, Blizzard joins the battle for achievements by bringing them to the Blizzard franchises.
This probably doesn’t come as any surprise to Burning Crusade owners, but think on this… you can’t play Wrath of the Lich King without the core game and the Burning Crusade expansion. New adopters of the WoW haze will be investing a good deal of money, before monthly charges, to get into the full experience of Lich King.