One of the biggest problems I see on SO is repliers tell the OP they are "doing it wrong" and not answering the OP's question. Typically you'll see some smartass reply with, "Why would you want to do that? You're doing it wrong. Do it this way, here's how."

These replies infuriate me. The OP knows what his problem is and he's asking for an answer. He doesn't need a new problem to solve. He doesn't need to know what your opinion is about solving the problem. He needs a solution.

One example: I was searching for how to solve a RVM and rails configuration problem on OS X. I typed the error message from the console into google, and found a SO question that was exactly the problem I was having. But instead of providing an answer, the most upvoted comment was to uninstall everything and use homebrew because "you're doing it wrong" without homebrew.

That's nice and all, but I've had a rails and rvm setup on my laptop for 2 years without homebrew, and, like the OP, I don't have time to set that up now. I just want to fix this one configuration error and get back to work. I quickly went back to Google and found the solution on another rails forum.

Granted, this is a problem with a lot of internet forums, not just SO. But it drives me nuts.