I just saw this news about research that says you notice compression artifacts less if you like the content of a particular video clip:
Using four studies, Kortum, along with co-author Marc Sullivan of AT&T Labs, showed 100 study participants 180 movie clips encoded at nine different levels, from 550 kilobits per second up to DVD quality. Participants viewed the two-minute clips and then were asked about the video quality of the clips and desirability of the movie content.
Kortum found a strong correlation between the desirability of movie content and subjective ratings of video quality.
(The original paper seems to be here, beyond a pay wall.)
Makes me wonder about the classic test footage with the calendar and the model train!