MATE is a simple, neat destop that
Using Xubuntu here for that same reason. Not to mention the fact that I have a lesser machine (an eMachines EL1358G) with not quite enough RAM to run full-on Ubuntu. Canonical seems to have done some nice things with its spin of XFCE used here.
The Ouya does that better at lower cost, no soft-mod required.
Not to mention the availability of non-game apps on the device. Does TuneIn ring a bell? Not sure if the Ouya has the right video innards, but it could probably run Netflix or Hulu and become yet another Roku competitor.
Roku units are god-awful for playback of local content.
I'm running Plex on mine, which seems to work well. Gotta set the server up on a pc, but it seems pretty low impact.
Twonky is better for that kinda' thing. Just sayin'.