TRON (1982) - Incredibly dated (with 8-bit arcade cabinets and mainframe computing considered the height of technology). The then-experimental SFX was also pretty rough in places with the mesh between the actors and the CGI scenery often jarringly bad (the actors keep on glitching out and going black-and-white due to the blending 'washing out' non-CGI colour).
However, the technical quibbles aside, it remains a fairly good early-80s Disney romp with all the tropes and cliché characterisations seamlessly ported into the digital world. If you get the chance, read
Brian Daley's novelisation of the movie. It includes a half-dozen deleted scenes and does an excellent job of filling in the blanks of plot and the characterisations, explaining otherwise-incomprehensible moments in the movie (including a few 'looks awesome but why?' scenes in the movie).
For all it lacks the technical sophistication of the recent reboot/sequel, TRON: Legacy, the original had a certain narrative purity and science-fantasy innocence that the more recent offering lacks.