I'm a big dork about the original 1982 Tron, an endearingly dated computer-geek science-fiction fantasy. I love the sound design, the art direction, the light cycles, the disc wars, the villainous Sark, etc. For a 90-minute family friendly film, it draws the viewer deep into its own cyberworld and doesn't speak down. It can be enjoyed as pure entertainment or a Matrix-like excursion, rich in fictional nerd terms and culture.
I don't know if the sequel, Tron: Legacy (Disney, 12.17.10) will be any good, but I'm really, really looking forward to it.