My favorite is when buying a TV or helping a friend buy at TV when the salesperson goes into the Monster Cable pitch the convo always goes something like this:
Sales: Now that you have this awesome TV, you're going to want the best possible picture right? Well these are the best cables on the market and will ensure the best possible quality there is!
Me: It's a digital cable, right?
S: Yes
M: So how does it do zero and one better than other cables?
S: Well it has better shielding, and will last much much longer than anything else out there, you need this cable! Would you fill your Ferrari with regular gas??
M: There are different grades of gas, HDMI cables either work or they don't. For that price I could buy 20 regular HDMI cables, so if they do falter, I can just replace it.
S: *defeated look for a moment* Well you definitely want to protect your TV, right? Let me tell you about our warranty.....