I was in the same spot last week and semi-reluctantly picked up the Kindle Fire. It is powerful, provides a great set of stock features, and has great consumer buy-in. I think Amazon has a winner on its hands, and is really the only viable (imho) alternative to the Ipad. Now before you guys skewer me up for saying that, let me explain what I mean.
Amazon has the first android tablet that comes with a set of comprehensive services, right out of the box. Amazon has their own app marketplace, music store, movie/tv store, book store AND cloud storage, delivered in 1 bundled, easy-to-use package. This is similar enough to some of Apple's services to make the user experience compete at a lower price point.
And, if you aren't going to use the device in the way Amazon desires, there are options for custom ROMS, rooting, side loading apps, etc. This is another win-win.
I am actually very happy with the Fire, even in stock form. I had CM7 on it for a few days, but reverted back to stock.
The Fire does lack expandable storage, but that can be overcome with Amazon's cloud (and really, outside of storing music/movies, how much space do you really need for apps?) if you can keep running the stock rom.
I almost bought the Acer A100, but found the display (especially the viewing angles) to be too big of a shortcoming to make up for the other "features" it has. The camera, for example, seems like a nice feature, but in reality I doubt I would use it. Bluetooth would also be a nice feature, but again...I doubt I would have a good way to use it.