[popo]

With the usual proviso that we're looking at technical quality and not artistic quality, I would still want as much data to start with regardless of the output medium. After a point there may be reducing benefits, but it is always easier to throw away excess information, than try to recover it when it isn't really there. For decent screen pixel level output and to overcome the limitations of bayer pattern sensors, I'd like 2x the resolution per axis (4x area) so in that 1080p example, I'd want ~8MP as a starting point after any cropping. Affordable 4k displays are here, which is not necessarily the same as "good" 4k displays, but I can see them being much more common shortly. For pixel level quality there, I'd be targeting 16MP+. You may counter-argue, people probably shouldn't be pixel peeping at 4k...