They seem to be growing more ubiquitous by the election season: campaign ads — not for the candidates running for public office, but for ballot measures proposed directly by the voters.

In the decade of the 1970s, 24 propositions appeared on the California ballot. Between 2000 and 2010, that number more than quadrupled. And the amount of money pouring into the campaign committees for or against these initiatives means the ads on both sides are becoming more sophisticated and almost omni-present in the run-up to an election (at least on the networks).

Dull and wonky, biting and satirical, even downright silly, we've got a few of the more interesting ads this season, and we even snuck in a classic from the '80s. Check out the video slideshow above.