Man, after finally seeing this show in HD, it's almost painful to go back to the old DVDs now. I tried watching Where No One Has Gone Before last night, and I swore the picture looked worse than ever.
That is one I'm definitely looking forward to seeing remastered. Especially with all those incredible nebulas, starscapes, and warp effects (and that shot of Picard almost walking out into space should be cool to see in HD as well).
I may purchase S1 solely for this episode.
Other seasons will depend whether they fix shots that need a little "reimagining". So far it seems that they won't, but who knows, anything can happen.