An argyle sweater is a knitted article of clothing with a diamond shape pattern. It is typically seen or worn by shallow douche bags that attempt to look wealthier and more important than they really are.
Robbie: Man, I'm thinking of buying an Argyle Sweater.
Timothy: What? Robbie, Ew.. do you want to look like Mr. Rogers puked all over you?
Robbie: not necessarily, you are right man, I'll just buy a bow tie instead.