Arkel makes some nice bags for commuting, that have nice straps for carrying around off the bike.

Arkels are really well-made. Perhaps not as impervious to the elements as Ortliebs, but I'm also unlikely to be cycling in extreme conditions. Never say never, tho!

I have the Shopper for grocery trips. For commuting I use one of their front rack touring panniers on my Dahon. I put it on the left side, and I like that I can adjust the hooks to avoid heel strike.