There's a mindset stridently advocated that, when an election looms, it is your duty to vote! Tom Hanks would like to spank nonvoters and Amy Dunham compares voting to losing one's virginity. Holy cow! Then there's the old saw, "Bad politicians are elected by people who do not vote." This is pure crap, in my opinion! Bad politicians are elected by people who either voted without thought or voted strictly for their own selfish interests.
Anyway, this sort of argument should not be bought without thought.
There are options. If, in your judgment, the two major parties came up with losers*, the conscientious citizen may do one of several things:
1. Hold one's nose, and vote for one of the major party's candidates.
2. Vote for a third party candidate.
3. Don't vote.
This article from Slate makes a cogent argument:
Of course, if you're less concerned, or have obligations that would keep you from becoming informed, do everyone a favor by staying home. You do less damage.
*Like in 2004.