I'm currently using an Intuos4, 4x6 (though actual measured dimensions are closer to 5x7, really). I am VERY happy with it, and would recommend it to anyone. Ran me .. 250-300ish, if i recall.

Most people seem to agree that Wacom is definitely the way to go, so put your money there if you possibly can. Most people also seem to agree that for typical use, the lower end Bamboo is quite acceptable (and really, i can't think of a reason not to get one, unless you can justify the higher cost for a higher end model).

Also, size is a factor. Mine is perfect for me size-wise, any larger and i'd have to start using large arm movements that are inconvenient for the way I like to use it

Hope that bit of summary helps you.