I love my Ortlieb front roller classics, but I do wish they had a handy external pocket for phone and keys. On any everyday basis I carry a change of clothes and shoes, lunch in an insulated bag, a tablet, a lock, an extra headlight, some bungee cords, and my purse.
It would be really useful to have a waterproof pannier that looks like a regular briefcase rather than a bike-specific item. Po-campo makes one, but it's not quite what I'm looking for.