Appeal to the People

If you suggest too strongly that someone's claim or argument is correct simply because it's what most everyone believes, then you've committed the fallacy of appeal to the people. Similarly, if you suggest too strongly that someone's claim or argument is mistaken simply because it's not what most everyone believes, then you've also committed the fallacy. Agreement with popular opinion is not necessarily a reliable sign of truth, and deviation from popular opinion is not necessarily a reliable sign of error, but if you assume it is and do so with enthusiasm, then you're guilty of committing this fallacy. It is also called mob appeal, appeal to the gallery, argument from popularity, and argumentum ad populum. The 'too strongly' is important in the description of the fallacy because what most everyone believes is, for that reason, somewhat likely to be true, all things considered. However, the fallacy occurs when this degree of support is overestimated.

Example:

You should turn to channel 6. It's the most watched channel this year.

This is fallacious because of its implicitly accepting the questionable premise that the most watched channel this year is, for that reason alone, the best channel for you.