Just to get going I'm posting these suggestions for new license slogans:
Alabama: COME ON IN AND GITCHA SOME.
Alaska: WE CAN'T ACTUALLY SEE RUSSIA FROM HERE.
Arizona: WHERE AIRSTREAMS GO TO DIE.
Arkansas: HELL, YES, WE SELL LIQUOR ON EASTER AND CHRISTMAS.
California: WE REALLY PISS YOU OFF, DON'T WE?
Colorado: WHERE PROACTIVE HOLISTICISM EMPOWERS INTROSPECTIVE PERSONHOOD.
Connecticut: FIRST IN LYME DISEASE.
Delaware: IT AIN'T DOVER TILL IT'S DOVER.
Florida: WE GOT DOZENS OF PEOPLE WHO STILL SPEAK ENGLISH.
Georgia: SORRY, WHAT WAS THE QUESTION?
Hawaii: NO MORE "I GOT LEI'D" JOKES, OKAY?
Idaho: SERIOUSLY, WE'RE STILL SEEING THOSE BLACK HELICOPTERS.
Illinois: THE STATE THAT'S MOSTLY A CITY.
Indiana: WHERE FOLKS ACTUALLY VOTED ON WHAT TIME IT WAS.
Iowa: GIVE US ONE MORE SHOT AT ETHANOL, OKAY?
You can see the rest of U.S. states and some Canadian provinces at the link.
----
Found by Bad Art.