I can only assume you haven't seen
Wrath of Khan very recently!

It has NOT aged well. Incredibly bad acting/overacting, dreadful special effects, all in all a mega cheesefest. I've not seen the DVD, but as for the film itself, I'd say it's dreadful. To each his own, of course.
Galaxy Quest is a gem that didn't really get it's due, IMO. It manages to poke fun at Star Trek without being disrespectful to it, and it stands well on it's own merits if you're not a Trekkie, or even a sci fi fan. I particularly loved Alan Rickman's role (by Grapthar's Hammer!).
Now we come to an areas I disagree- I really loved all the LotR films, and particularly the extended versions. Actually, the extended versions of the first two are dramatically superior to the theatrical versions. Despite being 1/2 hour longer, they actually improve the pace greatly. Maybe it's just that I'm a huge fan of fantasy & sci fi in general, but I think they richly deserved their "Best Picture" honors. And unless you just hated the movies, I can't see what's to criticize in the DVD packages. The sound & picture are both first rate.
Ditto the
Star Wars films. Like most hardcore fans, I think
Empire Strikes Back was the best, but I liked them all. Rating the DVD is a very sticky matter, though. On the one hand, it would be very hard to find fault with the technical standards of the set. The picture is stunning, much better than most new films, and certainly amazing for the age. Likewise I thought they did a superb job with the soundtrack.
BUT, this is a biggie, I'll never forgive Lucas for the hatchet job he did on them, content wise. It's scandalous that a movie on the AFI's list of the top 100 films of all time get mutilated like this. If I rate the DVD set without regard for the artistic quality, I say it's an out of the park home run. But I can give the total effort perhaps a 6.5-7/10. I could see one day buying a Laser Disc player just to see the "real" movies again.