I'd recommend a Wacom so far like everyone else. I have an intuos4 Medium and I've used the bamboo a lot too. They perform pretty flawlessly. However some of the cheaper brands aren't too bad (I bought a cheap Trust tablet last week just to try it out and it performed very well for the price). If you've got the cash, I'd definitely go for a Wacom but it is worth doing a little research on some of the other brands I think.