I'm watching TNG right now on DVD, and I admit S1 and 2 look rough but they always did. The rest of the seasons always looked fine to me.
From the OP's picture up-thread I'd ask what kind of TV he is using, because judging from that screen-cap (setting aside any oddities with taking a picture of a TV, uploading it and then putting it here) I'd ask what kind of TV he is using. I'd guess a CRT or early RP.
My TV is an HD RP and TNG's DVD looks fine and perfectly watchable for me.
HDTV with HDMI connection.