Archos has a number of android 2.2 tablets, screen sizes include 2.8, 3.2, 4.3, 7 and 10.
There are lots and lots of android tablets from a whole bunch of manufacturers.
The apples have great screens, they can’t really do more than the android tablets, and in many cases less but the screens are great.
And so far with the exception of maybe the Samsung, they all suck. Most, especially those from the likes of Archos, are under-powered media players with Android slapped on them, branded as a tablet. I remember one was so bad a reviewer initially didn't even publish the review. When they finally did, it was horrendous, the worst thing they've ever reviewed. The device was pretty much useless in every respect.
In general, it's "you get what you pay for" vs. an iPad. If it costs 1/4 of an iPad's price, then that's what you're going to get.
And what's a 2.8 inch "tablet"? That's like an iPod, and 3.2" is closer to an iPod touch. 4.3" is like one of the larger Android phones. Tablets really don't begin until 7" and up, although arguments could be made for 5".
The AMOLED display on my Samsung GalaxyS “Fascinate” is the best I have seen anywhere, on anything. I refer to brightness, clarity, and color saturation. Obviously, it’s smaller than my computer monitors or TV.