Unfortunately, you gotta do a little research to determine what's important to you. But, alot of the devices released last year all had the same innards, ie Tegra 2, 10.1" display, 1 GB RAM, running Gingerbread. The manufacturers tweaked their devices by offering an extra port, or slimmer design, or different skin. But at the end of the day, last year's devices are pretty much the same in my opinion.
Weight and form factor will be a differentiator, so I highly recommend getting to a store that has a decent selection and playing with each one. Also, I suggest checking out the Tablet Forums here and stick with a device which has a large amount of threads and comments (ie the Transformer or Galaxy). This should translate into a better community in case you encounter problems. I own the Lenovo Ideapad K1 and really like it, but there is very little discussion about the device and it has very little developer support. It's not a problem for me because I'm not rooted and basically use the tablet for reading, web, games, etc. But if you're gonna get into hacking the device, you should stick with something more popular.
As for the newest and greatest out right now, it's gotta be the Transformer Prime. Quad-core Tegra 3 in a sleek aluminum body makes for a pretty sweet device. But there have been complaints so do some research.
I hope this helps. Good luck picking a device.
