I have the Ortlieb Back-Roller Classics. They are very big, very durable and very waterproof. The only thing I do not like about them is that they are also very heavy at about 3 lbs each. I'm toying with the idea of starting to search for a lighter alternative, but I've not put any effort in to that yet. I really wish my laptop would fit in to my Revelate Designs Framebag or Viscaha Seatbag that I use for bikepacking. I would love to loose the weight of the panniers and rack but I'm not sure how else to carry my laptop without switching back to a backpack, which I will not do.