The heroes are truly heroic: the noble and powerful Autobot leader Optimus Prime is one of the most iconic characters of the 1980s, and getting the original voice actor (Peter Cullen) to give him life was a stroke of genius. The villains, meanwhile, are just plain evil: Decepticon leader Megatron (voiced by Hugo Weaving) is motivated by absolute power, and his soldiers are not above a bit of wanton destruction to achieve their goals. Mix in a bit of mysticism in the form of the Allspark, the source of life for all Transformers, and the result is pure cinematic magic.
Its not a perfect film: there are some characters and sub-plots that are unnecessary and which go nowhere, and at almost three hours, its a lot of movie. But the Transformers themselves, rendered in CGI, have a very realistic size and weight on screen, and look particularly good as they switch from one mode to the other. Moreover, director Michael Bay is smart enough to realise that appealing to kids doesnt mean pandering to them--the cutest robot on screen is a manic little psychotic killer with the apt name Frenzy. The humans in the film, meanwhile, keep the film grounded, whilst never detracting from the real robot stars. Unlike The Matrix trilogy, which tried to be too clever, or The Lord of the Rings films, which were too clever, Transformers is probably the best science fiction epic since the original Star Wars trilogy. --Robert Burrow