A person who thinks pretty much everything is amazing, especially music. Their opinion is usually invalid about things, though if they don't like something then chances are its legitimately bad. They generally wear skinny jeans, black socks, shirts one size bigger than they are, and 90s vans.
"Hey did you listen to the new Foster the People Album? It's amazing!"
"Shut up Brian, you're a fakester your opinion doesn't matter."