Whos to say you need to act like an idiot, or say cheesy phrases and grin like an idiot on drugs? If you think you look too bad to be on camera, look at Jabba the Hutt. Hes not exactly attractive and he got in a major film. I am in no way saying you look as bad as him, but im just making my point. You would be there as the person passing the information on to the avid viewer who would be interest in the product review or the subject at hand and not how you look or act.
In fact whos to say you need to be on camera at all? You could just do voice overs of soft focus slo-mo camera pans of the product at hand.
The sensible and totally viable possibilities that dont involve a dino-suit are endless.
(Thats something ive said to my wife, but thats another story....)