After a decade of piecemeal showings on cable and home video, the Back To The Future trilogy has finally been fused into one souped-up DVD box set, choked with enough special features to secure its place as the preeminent blockbuster franchise of the '80s. As designed with whiz-bang style and clockwork precision by director Robert Zemeckis and writer/producer Bob Gale, the three films are seamlessly integrated into a whole, but they were better when kept apart. When the films are taken one at a time–preferably with several years between viewings–their repetitious catchphrases, over-the-top performances, and hyperactive jaunts across the space-time continuum can create the sort of sugar high that makes movies seem like theme parks. Seen together, the trilogy gets so knotted in alternate realities, multiple roles, frantic mugging, and mountains of exposition that it seems in danger of triggering an epileptic fit, or at least a few dips into the Excedrin bottle. Pioneers of the louder-is-funnier school of blockbuster filmmaking, Zemeckis and Gale, along with director Steven Spielberg (the series' executive producer), were responsible for the notorious 1979 flop 1941, but they clearly refused to take its gross excesses as a cautionary example. Before getting chewed up by its own relentless Rube Goldberg plot machinery, the trilogy gets off to a mostly rousing start with 1985's Back To The Future, which sneaks a sweetly Oedipal premise into a gleaming model of Hollywood craftsmanship. Set in the backlot town of Hill Valley, an amusing repository of the Reagan '80s (Libyan terrorists! Pepsi Free! Huey Lewis!), the film stars Michael J. Fox as a high-school kid who hitches his wagon to Christopher Lloyd, a crackpot scientist who fashions a time machine out of a DeLorean. When Fox is accidentally shuttled back to 1955, he unwittingly takes his father Crispin Glover's place in meeting his mother (Lea Thompson), so he has to conspire to bring the two together, thus ensuring his own existence. In the name of family entertainment, Zemeckis and Gale too often fall back on broad, obvious gags (the bully in all three films, played by Thomas F. Wilson, is a particularly irritating character), but they glean endless fun from Glover's inspired croaking and Fox's uneasiness with his mother's advances, not to mention the otherworldly chords of Mr. Edward Van Halen. After the first film was a box-office smash, the next two were shot back-to-back for release in consecutive summers, but the franchise mentality sucks away most of the charm. Overstuffed with cluttered production touches, self-referential jokes, forking timelines, metaphysical quandaries, and more dual roles than even Peter Sellers could handle, Back To The Future Part II squanders every ounce of audience goodwill, then has the audacity to end with a trailer for the third film. Shuttling through three different time periods (1955, 1985, and 2015), Gale's script actually makes sense of some dizzyingly complicated time travel, as Fox and Lloyd try to stamp out an alternate world ruled by Wilson, who gets rich off a sports almanac containing decades of winning bets. The chain reactions from past to present to future raise all kinds of comic possibilities, but the film offers little more than stridently silly voices, a battery of shameless product plugs, and ironies that wouldn't suit a below-average episode of Futurama. Though no less synthetic and impersonal, Back To The Future Part III restores some of the original film's innocent fun by simplifying the space-time conundrums and sticking to a more conventional Western adventure. This time, Fox tries to rescue Lloyd from an early demise in 1885, but an empty gas tank and Lloyd's blooming romance with schoolteacher Mary Steenburgen complicate his efforts. A breezy curtain call for everyone involved, Part III ekes mild rewards from its modest ambitions, which is more than could reasonably be expected from a lame-duck enterprise. For those who possess the energy to make it through the entire trilogy without reaching for an oxygen tank, the DVD gives new dimensions to the word "exhaustive," with a bevy of deleted scenes, commentary tracks, making-of documentaries, animated pop-ups, and a live Q&A session with "the two Bobs." In a trilogy where more is more, the complete experience is too much of a good thing.