Hey there Valiant :)
Well, I know you said that you don't want a Wacom, and perhaps I am a tad biased. (Okay, a lot biased) but depending on what you're planning on using your tablet for, it may be for the best to go for a Wacom anyway. If you can't afford the Intuos4, perhaps even the Bamboo? The reason why the Wacom tablets are more expensive is because they really are the best, and that extra bit of money can go a long way in terms of quality of your output!
I also know that now that the Intuos4 has come out, the slightly older Intuos3 has dropped a lot in price, so you could look at that!
I took a long time to decide what kind of tablet I wanted, but almost every review I've found online said that the Intuos was worth the price jump. If you're not convinced/are sure that you can't spend that much however, there are quite a few alternative options:
UC-Logic / DigiPro - These tablets are, from what I've heard, a solid and inexpensive option and are compatible with both Windows and Macintosh. They would be a good choice, but a couple things detract from it such as the pen itself requiring a battery, and apparently heavy pressure will create an unpleasant scratching noise.
The Aiptek Tablets - These are apparently very lightweight, and while a little bit more expensive than the Digipro line, come with a couple of advantages like plenty of macro keys and a higher pressure sensitivity level (twice that of the newer Digipro) ... (but half of what the Intuos4 has. Just sayin'. :D )
There are a couple of others out there, but Wacom really has dominated the market for quality tablets. Feel free to give a quick google search on something like "Graphics Tablet" and I'm sure you'll find a mass of reviews and recommendations on they buying of your new tablet!
Good luck, and I hope I helped some :)