I would get the Galaxy Tab 10.1, except for two major flaws - there's no HDMI (/miniHDMI), USB or MicroSD ports capability, and instead they force you to use a separate proprietary connector for each of those capabilities (except for MicroSD, where you're just **** out of luck). The proprietary connector thing is the main reason I won't buy an iPhone. I'm a Samsung fanboy and even I can't recommend it.
I'd really recommend the ASUS Transformer, especially if you get it with the dock. That gives you an extra microSD slot and increases battery life to 16 hours, and obviously it gives you a keyboard too. Also, the screen is an IPS, compared to all the other high-end Android tablets, which just have TFTs.