Speedhunters is the first website I always introduce to people who have a dabbling interest in cars. They cover a ton of aspects of car culture in general, often feature some very interesting builds, and they always have absolutely amazing photography. Similarly, for people who might have a slight interest in MMA, I often point them in the direction of Fightland. The articles themselves tend to be more on the light side of things, both in content and depth, but I actually think for them that's a good thing. It's enough to get allow people to get a feel for the culture without overwhelming them with technical details that might go over their head. Edit: I can't believe I forgot to mention, Bleeding Cool, Comic Book Resources, and Comics Alliance are all great sources for comic book fans.