Pedestrians, cyclists, and people on electric scooters/ mopeds who flaunt the law.
Here in Ontario, pedestrians pretty much have the right of way in most circumstances; much more so than in N.Y.S., where I'm originally from. But people push the boundaries, and behave so erratically and even dangerously. Just dealing with other vehicles is bad enough. But this kind of stuff makes driving an anxiety-riddled nightmare.