Get rid of one dog law: BSL in any shape or form. End of.
Change one dog law: Much harsher punishment for animal cruelty. Animal abuse should be a felony everywhere, and it isn't. Plus, Fable's adoption contract? "Have you been convicted of animal cruelty in the last 3 years?" WTF? How about EVER?
Create one dog law: This is where it gets tricky. For me, the fewer laws the better. Mandatory spay/neuter, anyone? Most of the good ideas could so easily turn into something overbearing, threatening just the resonsible dog owners. I think cracking down harder on the decent laws we have in place is better than making more. I definitely could get on board with the poop law, though.