When I commute to work I use the Detours Toto Urban Pannier. These are easy on and off the rack yet ride securely. The handles make it easy to carry into work. I haven't used them in rainy conditions so I cannot attest to how they would perform in the rain. They do come with rain covers. I don't feel unbalanced with a single pannier. I use two panniers only when carrying extra items to and from work. Most of the time a single is all I need.