Forrest Gump Though the film itself remains a classic due to its storyline, the scenes where Forrest meets various figures from history (President John F. Kennedy, the scene at Ol' Miss, John Lennon on The Dick Cavett Show, etc) look dated compared to modern holographic technology.
The Net Since this film's release in 1995, technology has drastically changed and identity theft and hacking are much more widespread. However, this would be pretty cool as a remake.
Titanic Though the film was probably the most-loved film of the '90s and has even been re-released in 3D, the original film hasn't aged well because of the now-outdated technology used to make some of the crowd scenes. In fact, according to the Huffington Post, there was one scene that was changed for the re-release of the film: the night sky scene. The director put in the actual placements of the stars at the time the ship sank.
Flubber Flubber screams "I'm computer-generated" much like Bit does in Tron. It also looks like the filmmakers at Walt Disney used the same or similar technology (albeit maybe an earlier version of such) as they did in Hollow Man.
