It looks nicer than the original PS release, but it has worse quality music. Not really worth getting if you already have a copy of VII I'd think.

Dust would be an interesting game to get your opinion on, I think. It's great fun from the little I've played of it, and it's probably not as well known as the other on your list. I'm also interested in your opinion of VIII for reasons already mentioned. It's my favorite FF game, but it was also my first FF game. I'm always interested in seeing what others do or don't like about it, though.