I know someone like this, not so much the part about not letting me get a word in, but the "top of the line", best of everything nonsense.
At first I thought maybe I was jealous but then I realized that I wasn't, I just don't want to hear about it ALL the time! If I find a product that I like I will certainly tell friends about it but it is sooo unbecoming to brag.
It has gotten to the point where I don't even believe her sometimes because it just goes on and on and on.
(BTW...this person is also someone who thinks everyone wants to date her...even though she is married. You can't talk about a mutual male acquaintance without her saying how they wanted to get with her at one time or another).