What gets my goat is skiiers on a cat track, when they carve they take up the whole track. It's like their body stays near the middle but their skis go to the limits of each side making it damn near impossible to pass without being overly aggressive. Snowboarders on the other hand seem to have their bodies move along with their boards when they carve so you can find a good time to pass. But on the other hand boarders and more erratic with their carves compared to the skiers predictable turns.
Skiiers on cat tracks going slow annoy me to no end. Another phenomenon I have been noticing recently is skiier congregations at the top of hills just before the runs. The skiers just stand in the middle of the trail so you have to go all the way around them to get past. Any half decent snowboarder has the common courtesy to move off to the side to strap in, and then they get going. But these skiiers just stand there talking about what run to do next without giving a damn about anyone else trying to get past them to get down the hill.