4. World Of Warcraft (2005)
A massively multiplayer online role-playing game that somehow managed to transcend the powerfully nerdish boundaries of its genre and become popular with 'normals'. Put in the hours and you could become a heroic leader of real troops and engage in sprawling quests and campaigns. Or you could be Leroy Jenkins.
More after the break...
3. Championship Manager 97/98 (1997)
Football is already a gigantic waste of hours, and Championship Mangaer was at times little more than an Excel simulator, but that didn't stop it being ludicrously addictive. It ended relationships. It drove grown men to tears. It made legends of rubbish players. Tommy Svindal Larsen! We love you!
2. EVE Online (2003)
This is the dream they had when they first created Elite in the 1980s. It's an online RPG in space, where thousands of players can come together to wage war, or soloists can carve out niches for themselves as humble resource miners. The time spent on this game in the past decade-and-a-bit is staggering, with tens of thousands of players investing hundreds of hours (and in some cases, large sums of real money) in building huge fleets of warships. The biggest battle so far lasted 10 hours, and destroyed virtual assets worth an estimated $300,000 in real money.