I haven't played anything but Dwarf Fortress in weeks.
At this point, I think it qualifies as genuine addiction.
It's amazing... The graphics are so simple, but the depth is incredible. I keep finding new and entertaining things to do.
Finally got a firm grip on 40d. Managed to build a couple fully-functioning forts. Withstood multiple sieges. Built some cool stuff. Got bored. 40d doesn't let you dig down as deep... And it's missing some interesting features...
So I finally got up the never to try DF2010 again.
Embarked to the side of a volcano, with a small river off to one side, and some forest to the South.
Had some problems initially... Designated too much digging, and too much dumping, and my dwarves didn't have time to do anything useful. Wound up starving everyone to death.
Tried again, reclaimed the fort... Did much better that time, but I completely neglected my defenses. Got a nice fort set up only to have everyone wiped out by the very first siege.
Third time's the charm, right?
This time around I've got a nicely working fort, complete with defenses. I'm not quite completely self-sufficient... But I can stay holed-up in my fort for a good, long time before I have to come out. More than long enough to deal with a siege.
And I've still got a lot of map left to play with... I've just occupied the upper few levels of the volcano. Once I'm completely self-sufficient I'll start working on a magnificent fortress. Maybe I'll tunnel down below, too.