Well, I would say I certainly have the motivation for the following:
Terrace (3 houses)
Small house
Barracks
Blacksmiths or wizard tower
Church (Sigmar)
After this, it being mordheim, I would like to take a trip downtown to the daemon infested slums and really make something crazy, but it would depend on my motivation by then.
Hell, I could make an a ruined brothel or something! Lol.
I might also make some large quick complete ruins, like the old Epic plastics.
Real world time commitments and wanting to paint/collect other stuff means I'm aiming for one building a month (or thereabouts).