GEICO

Purpose: To sell car insurance to the general public

Claim: People who purchase Geico Car Insurance are as happy as the Pillsbury Dough boy on his way to a baking convention.

Speaker: Banjo and Guitar-playing Geico spokespersons

Pathos: This ad makes use of an adorable character who giggles and sings along to the tune in order to make the audience laugh along and associate the product with happiness. 

Ethos: The Pillsbury Dough boy is a very well known and trusted advertising figure that because it is endorsing the Geico company it gives the car insurance some credibility. Pillsbury wouldn't place their name or character in the commercial if they didn't trust the Geico brand themselves. 

Logos: The logical argument made here is that when you purchase Geico's insurance you will become very happy, as happy as "the Pillsbury Dough boy on his way to a baking convention." This is just a descriptive simile to describe the piece of mind you'll have with good insurance on your car.