In Trash We Trust. Remember all the cool things your mother tried to throw out because they would rot your brain? (She's right, you know, but you do get used to the sickly-sweet smell.)
A tumblr by writer Michael Allan Leonard devoted to a wide spectrum of low culture sci-fi, horror, and fantasy imagery: comic art, superheroes and heroines, cartoons, videogames, pin-ups, vintage pulps and b-movie posters are plentiful in these parts.
Mostly PG-13, but your mileage may vary on whether it's safe for work, school, or any viewing over your shoulder by an authority figure with discerning tastes and no sense of humor.