I've got an old, crappy wacom tablet... It's only one of those 99 dollar ones, and not the one they sell now, either, but the first generation of them, with only half the pressure levels... It's still a wonder. If I ever get to the point where I'm not ashamed to show my art in public (You know those cartoon shows that shoe kids fan-artwork near the end? That's my level of ability. And some of them embaress me. ), I'm gonna spring for a new one.
I also had a tablet before that from a non-wacom company... I think Cross, if I remember right...
Don't. Just don't. Unless it's some really elite brand or something, just don't bother with a non-wacom... For the money, you can't beat them.