Bill & Ted is a series of two films (and their spin-offs) featuring Bill S. Preston Esq. (Alex Winter) and Ted Theodore Logan (Keanu Reeves) as two metalhead slackers who travel through time. The first Bill & Ted film, Bill & Ted's Excellent Adventure, was released on February 17, 1989, followed two years later by Bill & Ted's Bogus Journey.
Bill and Ted were portrayed by Alex Winter and Keanu Reeves in both films and they also provided their voice for the first season of the 1990 animated television series Bill and Ted's Excellent Adventures. The characters have also featured in other media including several video games and a comic book.
There were Game Boy, NES and Atari Lynx games released, which were very loosely based on the film's plot. The film Bill & Ted's Excellent Adventure was adapted to a PC title and nearly identical Amiga and Commodore 64 ports. The computer titles followed the original film more closely.
Source: Wikipedia, "Bill & Ted (franchise)", available under the CC-BY-SA License.