I've mentioned the TPZ ("Technology Petting Zoo") sets we have, as a resource for showing librarians around the state various gadgets. Mine consists of an iPad, Google Nexus, Samsung Galaxy, Kindle Fire and Dell Venue. In addition I have my own Kindle Fire HD and Asus Transformer. Having so many gadgets is a challenge, requiring different accounts and passwords to keep track of. The iPad stands alone, of course. Since I don't have any other Apple devices that had to have a completely new and unique account. For the others, I was able to set things up with my Gmail account, and the Kindles work with my Amazon account so they seem a little bit easier to manage.
So what do I use most? So far it seems to be the Kindle - it's a nice size, not too heavy to carry and accesses just about everything I need (especially anything I had from Amazon in the cloud). My personal Fire HD developed a display issue so I haven't been using that one nearly as much (still trying to figure out the problem and how to deal with it). I've taken the Galaxy on a road trip and used it for Skype in the hotel, that worked nicely too - I like the larger (10") display. When attending ALA I chose the iPad because it's smaller (I have the mini version) and found it very convenient - it seems to connect to wifi very easily. On a recent vacation I took the Dell tablet because it has a keyboard and I expected to be accessing email. Trying to type anything substantial without a keyboard is just torture! Sadly, both Gmail and Hotmail proved to be extra security conscious and put several obstacles in the way, so accessing email turned out to be impossible when overseas (happily, Facebook was much more agreeable and I was still able to let people know where we were).
I try to use all the gadgets for a variety of tasks just so I can be familiar with each. I've got MtLib2Go on all, assorted web pages bookmarked, and a few library apps on them too. It's been a learning experience to figure out the different navigation styles (especially with the Dell Windows 8!) but at least I'll be able to help others when they have a question about a gadget.