In unexpected ways, biking lets you be super lazy sometimes. For instance, why walk over to the community garden when you can ride out and fill a pannier?
Speaking of which, I’m really digging my Brooks rolltop pannier for my commuter. It’s waterproof, has a nice neutral tone look, and stays put nicely on a standard rear rack. I already have a set of Ortliebs for touring and grocery runs, but the simple hooks plus exterior pocket and interior organizer features on this pannier made it worth the impulse buy (and it was half price to boot!). Frustratingly I can’t find this exact model online but it’s most similar to the Land’s End Rear Pannier here (just with aforementioned pocket and organizer).