There are definitely quite a few brands out there with bags with good organisation! For bags that go beyond the main compartment with standard internal organisation (i.e. zip pocket + open slip pockets), I quite like Jenny Yuen, particularly the
Gatsby (two large pockets/compartments on the front and back, exterior zip pocket on the front, and two small snap pockets on the sides). Most of her other styles (e.g. Hitchcock, Sherlock, Esme) also have the two large pockets, whilst the Sherlock also has a zip pocket on the front.
Rebecca Minkoff's Matinee also has got a great number of exterior pockets, eight in total (two zip pockets on the front and back, two zip pockets on either end, and a slip pocket in front of each of those four pockets). I also like Botkier's
Trigger for its organisation, with two separate front and back compartments in addition to the main compartment. Botkier's interiors have a nice extra too, a long chain keyfob that allows you to use your keys without having to unclip them. Treesje's
Asher works quite well with two large zipped pockets on the front and back too, though its interior organisation is pretty standard (and the interior slip pockets are a little too shallow sometimes, in fact).
If you're thinking of internal compartments, some of Belen Echandia's styles come with a central zipped compartment that divides the interior of the bag. The styles I'm thinking of are the various sizes of the
Love Me and
Take Me Everywhere. The stock bags may have a removable central zipped compartment, though (it attaches with snap buttons and can be taken out to function as a pouch), but if you want one that's non-removable (i.e. sewn into the lining), you can probably request that if you customise a bag. The added plus of customisation is that you can add other extra pockets too, and the owner can probably advise you on what will and won't work.
I'm a pocket fiend too, though I'm mostly interested in midrange designers. HTH!
ETA: Oh, almost forgot to add! The Botkier Trigger has got two hidden slip pockets on the exterior too, under the triangular flap on the front and back, and the zippers on the front also lead to a "pocket" of sorts (a small space in the flap, can't store too much there, though). The hidden slip pockets are pretty secure too, since you can't really access them unless you unclip the strap that connects the front and back flaps.