When we bought our house, it was in desperate need of some TLC. There had been some work done at the end of the '50s (mostly to make some extra bedrooms in the attic) and at the end of the '80s, start of the '90s (kitchen built out and roof replaced, mostly).
We started with the most important updates (bathroom, which was from the '50s and floorboards which were partly rotten and eaten) and in general stripping the house till the brick outside wall. After that was done, the house was liveable, even though not all rooms were finished yet. So, early last year, we finished the bedroom (upstairs) (we moved in 2006), at the end of last year, we finished the kitchen, this summer we finished one of the two extra rooms (our "computer" rooms, we have that much space!) and as soon as we know what it'll cost, we'll have the driveway redone (we won't be able to do it ourselves).
So, still plenty of things to do, such as my room, the second part of the attic (only the bedroom there is done, 2/3 of it is still in a partial finished state), the hallway, the stairs, the hallway in the back of the house, the utility room... We'll be able to have plans until the day we die, most likely