The Bullshido forum - making fun of McDojos and wanna-be Ninjas like the infamous Ashida Kim. Very witty posters. Lots of funny photos and cool videos.
Fighting Arts Talking about pretty much every mainstream martial art, more serious. Doesn't tolerate much sillyness. Former administrator used to be in my judo class and told me about it.
Wrestlecrap Smarks (smart marks) poking fun at some of the worst wrestling gimmicks in history as well as being critical of today's stars. Lots of hilarity.