Like the topic said. 
What brand? What specs?
I don’t even know about anything but Wacom ones. I opted for the (relatively) cheap Graphire 4, smallest. Turns out I don’t even use it for Photoshop or stuff, just doodling in IM convos…
Whats your price range as this makes a huge difference in what you can get.
We need to know your budget, otherwise we can’t ask?
I have a 9x12 Wacom and have had one for a few years now. I’ve also convinced my last 2 employers to buy them as they are great for painterly work due to the pressure sensitivity. I haven’t had any experience with anything other than the Intuos models and wouldn’t go for anything smaller than 9x12.
