I love junk shop art! Naturalist prints of fish, oil paintings of ships - if it's mildly ugly, nautical, and costs $3....I'm there. My latest obsession is old oil paintings of volcanoes. Real fire and brimstone action too.
The paintings below are of the Mount Vesuvius eruption in 1771. Krakatoa (1883) would work well too. Don't ask me why I remember these dates. I barely know my wedding anniversary.