i just use one of them WDTV Live boxes, it was fairly cheap and it just works. plays the 20gb+ 3d rip of avatar i have no problemo, all big file size native 1080p stuff. the apps are alright (youtube, netflix, spotify etc.) but i only really use youtube and play videos via my phone. not too bothered about 4k myself as i don't plan on getting a new tv for at least a year or two.