What bothers me the most is going down the interstate and a semi does that along side another semi. Gets everything backed up with tail-gaters. Sometimes I'll just take a little break at the first available exit when that happens. I drive slower than most (speed limit) but I always stay on the right on the highway unless passing.
Side by side semis drive me nuts. I can have patient if one is passing the other, but not when they clog up traffic for miles and miles. If soap still came in a box this would be one of the issues that caused me to stand on it.