Are there any anime series u plan to watch as a challenge?

I'm planning to watch Higurashi no Naku Koro ni and Boku no Pico for a challenge. Reason being they're both often called the most disturbing in their genres.

I've started watching Higurashi. Yeah, it's creepy, but I doubt I'll get nightmares from it like a lot of people. My /normal/ dreams, ones which don't scare me much, are filled with suicide, murder and horror, so the series feels normal to me. I'm actually surprised; I find myself laughing and making jokes in the parts that are supposed to be scary.

As for Boku no Pico, it'll have to wait several years. It's illegal (at least where I live) to watch it before you're an adult, and I'm still in my early teenage years. Though I apparently have an adult's intelligence and knowledge, it's still the law. So it'll still have to wait.