Uggh, that last example looks pretty bad. The poor contrast and blocky pixels look about as bad as those new digital flatscreen tv's. There's nothing any post production software can help you with because it seems your raw capture is garbage in.
So, how good is your laserdisc player? And what kind of capture device did you use. Laserdisc video is analog so having a good analog to digital converter is as important as the player. The other thing is to be sure you have a computer that can handle video with plenty of processing power, ram, hard drive and all those equipment things that I don't fully understand.