Perhaps you need to go to a different store? Lego City is still by far the biggest representative in most stores I visit. Whilst they do have Star Wars, Marvel/DC, Minecraft etc, their own branded pirates, Ninjago and Chima represent a far bigger slice of their offering across their range.

If you're after something even more generic than that, Lego have always had "creative" boxes available as well. They've actually just come out with a new series: http://shop.lego.com/en-AU/Classic-ByTheme