Roku Photobridge HD1000 network media player photo viewer 15-16 16-17 (idle at menu) booting 15 slideshow 17
Scientific Atlanta 8300 hd dvr cable box off 21 watts idle 22-23 peak measured (starting up) 31
Scientific Atlanta 8000HD Explorer (HD DVR cable box) off 29 watts on 30 watts (idle, playing, recording all were 30 watts)
Note that cable boxes and media adapters, are also usually "always on".
DVR cable boxes, because of the 30 minute buffer that lets you go back in time, are always on, even if they aren't recording anything.