Contentious question to ask around here- there are a lot of evangelists when it comes to what equipment is best.

There is waterproof or not waterproof.
There is 1 big bag or many pockets.

Choose what style you like. I use 1 big bag without waterproof. Easy to pack, low cost, and I can line it with a trashbag if I want it to be waterproof.

Ortlieb, Arkel, Lone Peak, Nashbar, Axiom, and many more. Ortlieb and Arkel are very popular and offer very different style bags. Those would be a good place to start for looking at what you prefer.