IIRC, Wacom is essentially the industry standard. However, for casual use, most people will find the Bamboo series to be just as useful. I think it's a lower division of wacom. Essentially same thing, but less bells and whistles.
My bro bought the wacom and then stopped using it. It was putting $180 on the side burner. Luckily, he found an art student to sell it to. Otherwise, it's a pretty expensive, toy that collects dust.
Bamboo is good enough for most though.