Wow, I hate all of these things!
I absolutely hate people not using their blinkers and I really really hate people who can't drive the speed limit. Why would you drive 35 in a 50 mph area??!
I'll also add a new one. It's people who don't look in their rearview mirror. Now, I'm an EMT in the next town over. When I have to respond, it can take up to ten minutes. I have my big old blue light (That's very bright) and every once in a while, I get stuck behind a person, doing under the speed limit and not paying attention. Sometimes I'll even honk the horn a few times and they still don't move! Finally, they figure out that I'm behind them and pull over on the worst roads. How can people expect me to pass them on a blind spot? Now, you also have those people that flip out when they see the blue light and almost kill everyone thats driving around them. PLUS, all this always happens when the call is something life threatening. I never get stuck behind a slow person when the call is minor difficulty breathing!