Wacom is the best company for graphic tablets followed by.... nobody. their pretty much the only choice out there. thy have 3 types
1-they have the graphire this is there bottom of the line for the home user these are there cheapest ones and have 512 levels of pressure and . currently they are at graphire 3 which doesnt have much of a difference from the previous models other than shape
2-The second one is the intuos this is for the pro it has programable shortcut buttons high resolution (5,080 lpi) and 1024 levels of sensitivity a really cool touch strip that acts like the scroll wheel on your computer. the intuos is on its second version
3- The Cintiq This is their top of the line for people who draw things that will be printed and sold for alot of money it is only for people who will be making alot of money from their work (or rich people who want to get an expensive toy) This has 1024 levels of accuracy and a tablet resolution of 5080 lpi and a display resolution of 1600 by 1200 (for the 21 inch version) or 1280 by 1024 (for the 17 inch version)they go for 2499USD and 1799 USD respectively.
I have been into 3d animation and graphics design for the last 5 years and done internships from small production studios (10 employees) to big Game studios such as EA games and I have never seen anybody use anything other than Wacom. I have tried both the Intuos and the Cintiq and they are great you cant go wrong. as for the graphire I have never tried it but can imagine its great