Although it's really simple, I quite like the Alaska state flag:
The blue represents the sky and the Forget-Me-Not, the state flower of Alaska. The North Star symbolizes Alaska being the most northerly state. The dipper is for the Great Bear - symbolizing strength.
The provincial flag of British Columbia is nice:
The flag itself was derived from the centre shield in the province's coat of arms. The Union Jack with a golden crown symbolizes the origin of British Columbia as a British colony. The wavy blue and white stripes represent the Pacific Ocean. The setting sun represents British Columbia being Canada's most western province.
Just a side note, I once heard that the California flag was supposed to have a pear, not a bear. It was a miscommunication.