I've only had one previous experience with a tablet prior to getting the one I just got for Christmas, but my Wacom Graphire2 works very well. It's a refurbished one, so it was cheaper than the newer versions; but it works well anyway.
My tablet's screen is 4x5, so it's really bad if you want to trace pictures right on the tablet... but I find it works well for everything else, and it's small so it doesn't take up an insane amount of space on my computer desk. If you plan on doing that, or if you often find you like to have lots of space when you draw, then you should probably look into getting a bigger one.
They aren't hard to use, but it takes a little while to get used to it since it's not the same as paper and it's not the same as a mouse. The hand-eye coordination thing really comes into play. XD I found it took me about an hour to really get the hang of it though. ^_^; Good luck in your search.