I use a Wacom Intuis 3.
I've had it quiet a few years now.
Since they last so long, I really, highly recommend getting the best you can afford.
But in the same note I wouldn't go over maybe 160 or so, you don't need a professional artist $250 plus one.
I say this because I know what it's like using 'dated' and less expensive models.
It really makes a difference once you've had and lost so to speak.
You want to be on the higher end of tilt, pressure, sensitivity, response, and durability tech.
However, this is subjective because it really depends on what your doing.
I do a lot of fine art photo modifications and tweaks and paint with programs like Painter 11 and others that can really be held back by more basic tablets.
If you just wana sketch, ink, color fill, and do some shading a bamboo would rock.
Ease of use features are a must though in my opinion.
A tablet that has a few programmable buttons and a pen that does too.
Wacom is a good brand and company.
They offer good and consistent updates and help.
Their warranty is cool and even the basic tablets have nice features. (They gave me extra nubs with all mine! :3)
I really suggest reading some online tech reviews. :3 Those can be extremely helpful because good ones field test the complicated spec side of it, while offering human opinion too.
Nerds rock.
Luck.
They are soooooooooooo awesome.