I quit minecraft after playing it for 15 minutes. Just not my type of game I guess.
Anyways, I will pretty much always play World of Warcraft, until I find something better I guess. I quit for months at a time but I always come back at some point. I just started playing again because Cataclysm is coming and all the new content is pretty fun, but before that I hadn't played for 6 months or so.
Yeah Minecraft isn't my type of game either. I never had lego's so I don't see the appeal in building things like that. The only aspect of the game that would be interesting is building up weaponry to fight the creepers, but I may as well play civilization or Alpha Centauri for that.
I stopped playing wow in September. I just got so bored. From about June-September I hated every second of raiding, I was just doing it because I was a class leader and an officer and I felt that I had to. I kept up with the game until a few weeks ago so that I could still provide my mages with all the information, tips, and tricks they would need to make it through the changes since I couldn't guide them in game. I still think I'm the best mage in my guild, and on my server but that isn't enough to hold me. The last remaining thing that kept my attention was working the AH and making a lot of money. That was very fun for a while. But then I couldn't justify having to raid so I could work the AH. So I stopped. I stopped following info about wow, and stopped offering advice when I started following rift, so I suppose I fall into your category of quitting wow for rift, albeit I did it in a different way.