I hate commercials that repeat the same thing (in most instances 3 times) in quick succession.
This ad for Head On does it.
There's one for Relacore where this is said 3 times in a row (very annoyingly) - I can't find a clip:
Relacore commercial: "Why did your last diet fail? Stress increases Cortisol. Cortisol causes belly fat. Relacore reduces Cortisol. You need Relacore."