None, I have yet to see one reboot or remake as good as the original, which made it a classic.
Going to find any actor to play George Bailey when Jimmy Stewart owned that? Going to get better than Gable/Colbert in "It Happened One Night" or Bogart/Hepburn in "The African Queen"? Guess is depends on how and what we classify as classics.
Could the advance of CGI and technical improvements make a movie better? I don't think so. "The Hobbit" would have been much better had Peter Jackson not leaned on CGI and taken the same road he did with "Lord of the Rings".
That is not to say I would not like to have seen the Star Wars saga take a different path but that was in writing more than anything else.
Watch the making of "Aliens" on Netflix's "The Movies That Made Us", it is a marvel of human creativity and ingenuity and if CGI had existed then, I am not sure it comes off like it did or that I would have the appreciation for it that I do now.
"Jaws" had the Bruce the Shark issues and that is apparent in some scenes and putting the actual footage of a real shark in it only serves to accentuate that but it is still a classic with those flaws.