My lg plasma is old and have overscan on every input. I've tried everything, also in the service menu, without any luck. The funny thing is, if the tv think that you have connected a pc, then you don't have overscan. So you must:
1-Use the vga input (so far i can only with xbox360) OR
2-Use the hdmi BUT the source must have an output of 1360x768 (the native resolution of the plasma is 1366x768 so i have only 6 pixel black borders horizzontally) SO since ps3 doesen't support this resolution i have the overscan.
And, as far as i know, the wii u can only be set to 720p or 1080p so i think i'll have a problem here when WII U comes to Europe!!