The way the trailer for Tron (1982) should have been done: Saul Bass-style. ;)
Update: While we're writing about Tron trailers, here are a few more that SF Signal has highlighted. This first is a fan-made trailer for the original Tron that is exceptionally well done. The only demerit I can find in this video is that it completely ignores actress Cindy Morgan's character and that aspect (the love interest/sexual tension from a love triangle) of the movie.
This next trailer is the original from 1982. It makes for a good comparison between the two above and the two trailers for Tron Legacy.