Which logical fallacy does this example contain? dan richards is the best mayor cooperville has ever had because he told me so himself?

Begging the question

The answer is "ad hominem".

It is appealing to one's biases, feelings, or unique interests as opposed to one's intellect or reason. An ad hominem contention is one that is utilized to counter another contention, however it depends on sentiments of preference like in this example, instead of realities, reason or rationale.