I've been very happy with all the Wacom Intuos tablets I've ever bought. I've used Intuos 1, Intuos 3 and Intuos 4. Even that oldest one is still functional after years of heavy use.
The only Wacom product I've been disappointed with is Cintiq 21UX. I thought it would be like drawing on a real paper but there's a gap between the screen and where the pen tip touches the surface. It also is quite heavy and got pretty hot after a while. I haven't used the new models though so they might have fixed it.