Definitely Wacom. No other brand comes close to how good their tablets are.
Intous 4 Medium / Bamboo Fun Pen & Touch Medium are my suggestions with Intous 4 being the better but more expensive option. I use the bamboo fun A6, it's a bit small but works for me. It set me back around $100 a little more than a year ago. If you REALLY want an amazing tablet, which probably is very unnecessary to start off with, I suggest you look at the cintiq series. The cheapest Cintiq is outdated and not particularly recommended so you should look at the 21UX V2 which goes for around $2500. Since your budget was $200-400, Intous/Bamboo are your options to choose from
