I'm lucky enough to have now set foot (and found a at least two geocaches) in all 50 US states. That said, there are admittedly a few states in which I've not really done much else. So our new goal is to see (inside, whenever possible) every State Capitol building. At last count I had 16.
And I've still yet to see Washinton DC.
But never fear, I'll be sure to correct these situations as soon as possible!