One of the original "bad" web sites run by Phil Plait, debunking myths, skewing quacks, and setting the record straight on most anything astronomy related. Phil Plait also keeps a very-often-updated astronomy(ish) BLOG.

Home of the million dollar paranormal challenge. James Randi's weekly commentary is excellent reading!

Ben Goldacre caries the torch in the UK, stemming the unending waves of quakery with reason and sanity.

Their own words: "The Skeptics Society is a scientific and educational organization of scholars, scientists, historians, magicians, professors and teachers, and anyone curious about controversial ideas, extraordinary claims, revolutionary ideas, and the promotion of science."

A female take on skepticism, covering all kinds of topics.

The site says it best: A Collection of Strange Beliefs, Amusing Deceptions, and Dangerous Delusions

The Skeptic Magazine is based in the UK. Debunking, sanity, and reason British-style.

The Committee for the Scientific Investigation of Claims Of the Paranormal

Very comprehensive health case-based site with explainations of numerous scams, pseudoscience, and insanity.

Reality-based Martial Arts

Clubb Chimera Martial Arts - UK-based martial arts school with an emphasis on realistic civilian fighting strategies as well as a mixed-martial arts approach to training.