Tablet - Photoshop Editing

I have owned just two tablets in all the years I've used Photoshop.  I started with the original Graphire, which I think might have been Wacom's first tablet, and I used it for year.  I upgraded when the Intuos 4 was released, and I am still using that all these years later.  If you have a Intuos 5, I honestly don't know what advantage you'd get from upgrading, unless you went to a large Cintiq.  I also own a Cintiq Companion 2 which I tried using instead of the Intuos 4, and didn't like it.  I prefer looking at the large screens in front of me, (I use a 32  inch central screen, and two 24 inch screens in portrait mode).  

If you have a bunch of dollars burning a hole in your pocket, accessories that I do like, roughly in order:

Logitech G910 keyboard.  The G keys are programmable and I use them to toggle workspaces, toggle Lazy Nezumi etc.

G602 mouse.  Really good feel, and switchable to fine control.  I own several high end Logitech mice like MX Pro, but I prefer the gaming mice.

3D Connexion Space Mouse, but not with Photoshop.  I'd hate to use SketchUp without it.

Shuttlexzf4 Pro V2 — a great tool for video, (I use it with Premiere Pro)

Razer  Orbweaver — has a bunch of programmable keys that you can assign to shortcuts.

Wacom is the most popular brand for sure. I'd try some different models in a store- their current Intuos line seems a bit flimsy and lightweight with cheaper build quality than older tablets (I still use an Intuos 3) which the more expensive Intuos Pro are better built.