Alright I'm sure we all have opinions on this one. The game can be good or bad but obviously it has to have a long quest to keep you going at it for hours or a tremendous amount of replay value. My most addictive game ever that I still play is Defense of the Ancients, otherwise known as DotA. It's a spinoff game from Warcraft 3 The Frozen Throne. If anyone else has played this, you'll know what I mean. The game last anywhere from a minute, if everyone quits, or a couple of hours. It's just got lots of replay value. Has anyone else played DotA?

Tetris. Screw your long quests and tremendous amount of replay value, I can sit and play that game for hours without even realizing it.

What you are experiencing is replay value. One of the requirements for being an addictive game.

a couple of hours is too long - 90 minutes should be the longest in DotA , whereas 60-70min. is the sweet spot of gamelenght .. after that it gets annoying ,because there is no improvement for the heroes ;)

I played several thousend DotA matches myself and still play it from time to time .. can't get enough of it *sigh* .. damned drug

I would have to go with Civilization 3 or 4. Both of these games I have played countless times over and I don't know how many times these games have caused me to watch the sun rise.

 When someone says replay value, they generally mean multiple endings, many quests, multiple characters, customizable characters, ect, not simple addictive puzzle games.

Elite Beat Agents

tetris attack

I would have to disagree. Replay value is anything that gets you to play it again. The simplest games can have replay value. Minesweeper has replay value but doesn't have anything from your list of criteria.

I have to agree with you. When the game gets to the 2 hour point it has probably gone on too long. I meant that the game can last that long, not that 2 hours is the ideal time. It can last a minute as well, but that means the game never really started. And yes DotA is like crack.