I've been looking for a PC game where:
1) I have a ridiculously high level cap;
2) Almost everything is customizable;
3) I can manage an entire city, or at least a farm.
Also, it should be an RPG.
Now, one of the three items can be left out (that is, any of the three), as long as the other two are still in. It's likely you would just throw out the third option, since there are nearly no Harvest Moons or Rune Factories on PC.
I do prefer all three though.
Actually, if everything else fails, number 2 is the most important to me. I love in-game customization.