The answer, obviously, is that they’re all controversial. And (as measured by talk page size) they’re the top-5 most controversial articles on wikipedia: see [[Wikipedia:Database reports/Talk pages by size]] (I’m discounting #1, “Main page”, for the obvious reason). The only surprising entry in the top 10 is #10, Prem Rawat, who I’ve never heard of outside wiki. But he’s some quasi-religious figure, so it makes sense. Chiropractic and Homeopathy make 11 and 12. And so on.
I found this page via the ever-popular arguing about the [[Monty Hall problem]] (if you’ve never seen the problem, do go and have a look but don’t come back here afterwards and talk about it because we did that stuff in first year maths at university). That’s followed by [[Climatic Research Unit email controversy]], so GW gets two in the top 20. But then its not till #43 that we reappear with [[List of scientists opposing the mainstream scientific assessment of global warming ]].
I think its nice that 0.999, and speed of light, are in the list too.
* Hutzler 571 banana slicer – reviews.