Evernote
I just got back from a business trip, and I may be slightly addicted to Evernote. Since the client we were visiting issues iPads to new employees, it made sense to take a work iPad with me instead of a bulky, heavy laptop plus power brick, and I've been using Evernote to work on some shared work documents.
What makes the iPad indispensable, and turns it from a nice toy into a usable tablet is the Logitech keyboard. While the Samsung Tab Pro 10.1 tablet with Polaris Office has all the functionality of the iPad and then some, the fantastic Logitech keyboard doesn't yet exist. Logitech says in May the ultra-thin keyboard folio case will arrive, but only for the Tab, not the Tab Pro. The Tab Pro 12.2in size can be bundled with a keyboard case, but is that too big? I'm not sure.
In every meeting, people pulled out an iPad with keyboard and started tapping away. I'd love to do the same with an Android tablet, but sadly I can't yet.