Always helmet, gloves, jacket, and steel toe work boots, then most of the time I also wear my riding pants. When my commute was under 2 miles, I wouldn't put on the riding pants, but now that it's around 20 miles, I tend to use them a lot more. If I'm just running in to town, I usually leave them home. The ironic thing is that those short trips where I (and many others) neglect a piece of gear is probably where I will need it! The areas that we feel most comfortable, short trips, etc. are where we're most likely to have an incident, since we travel that area more.