I recently bought the latest computer from Hardkernel ODROID, the ODROID C1. More on that in a subsequent article.
One of the things that I like about ODROID is that they seem committed to building a community, even to the point of publishing a slick monthly magazine where people brag about the projects they've been working on.
They're not the only ones though, and this fall and winter there's been a huge wave of cheap and capable boards coming out, some of them as notably inexpensive as the Raspberry Pi (which bootstrapped the whole genre much as the OLPC laptop created the whole "netbook" ecosystem) but more capable - with more RAM, more cores, gigabit ethernet, and more. Lists published at http://linuxgizmos.com/ringing-in-2015-with-40-linux-friendly-hacker-sbcs/ and http://www.bigboardlist.com