It seems there are three categories here.
Category #1: Stupid things gun owners say. Things like "stopping power", "knockdown rating", "one-shot-stop statistics" are big buzz words. For me, it's whenever you're trying to weigh the pros and cons, and someone simply says "it's not the gun, it's the shooter", which completely invalidates any discussion.
Category #2: Stupid things uninformed people say. This is largely the entertainment media (not the news), which have an anti-gun agenda, but I have to believe a large portion of them are just uninformed. Look at how much they screw everything else up. These are when cops on a crime drama ask law abiding citizens "why do you have a gun" or fudge up how guns work (my favorite example is a scene on lost where a guy pulls the hammer back on a Glock twice for emphasis).
Category #3: Stupid things stupid people say. Aside from our VP, who has given people a great defense to use in court (has that defense actually worked? anyway...), you have any of the following buzz words:
Gun Control
Common Sense Restrictions
But (after "I support the second amendment")
Gun Crime
Gun Show Loophole
Universal Background Checks
Lack of trust in the American people
Keep guns out of the hands of kids
...you get the picture