TRON: Legacy
I feel like this movie was truly ahead of its time in terms of vfx, CGI, and cinematography overall. (Definitely revolutionized de-aging technology at least.) I love the music, the soundtrack, and yes it doesn't stand out as much by today's standards, since the standard for CGI and VFX has caught up with it by now, but I honestly think that this movie, considering its release date, is an underrated gem.