This is the finest action movie of all time. And, yet, believe it or not, it's not the action in the film itself that makes this be the case. This is especially odd in a movie with a $100 million budget (in 1991!), with multiple huge explosions, with thousands of bullets fired, and scores of stuntmen used.
This movie is what it is, a perfect 10, because it takes the vision of one of the most imaginative directors on Earth, and realizes them almost perfectly with all the tools that fit the task -- actors, stunts, puppetry, models, and CG. Without the vision, this film would be nothing. Without the tools, this film would be nothing.
But, a little bit of background is due. This is the sequel to the Terminator (1984), whose premise was that a near-indestructible cyborg is sent by evil self-aware machines from the near future to destroy the mother-to-be of the military commander who would lead the humans to a victory over the machines. Oh, and this terminator machine would come from a time of war between men and machines which followed a nuclear exchange that left billions of people dead, first. In Terminator 2, John Connor (the commander-to-be) is about 12 years old, and his mother (Sarah) is feverishly trying to prepare him for his fate, even as she tries to stop the factors that will lead to the nuclear war and the entire terrible future that made all this necessary. The machines now send a superior, more intelligent, shape-shifting cyborg (T1000) into the past, to kill John himself. Meanwhile, future-John reprograms the ex-evil Terminator (T101) from the original film, and sends him into the past to PROTECT John against the T1000.
That's your basic plot. It does involve travel into the past, so it immediately presents a time-travel paradox which can't really be resolved. In order to even try watching this movie, you MUST LOOK PAST THE PARADOX. If you don't, this movie has zero credibility, and is not worth your time.
What happens after the two terminators appear in the past is a wild ride rife with macho action, dark reflection on the nature of man, and a few rays of hope, here and there. Schwarzenegger (the good terminator) and Patrick (the bad one) make for such effective foes that the times they meet on-screen are completely breathtaking (and odd, given that you repeatedly see the relatively slim T1000 through Arnie through a wall or two). Hamilton, as Sarah Connor, is a wonderful character -- tough beyond all belief and completely focussed on preventing the nuclear war and ensuring John's safety, yet clearly a little out of her mind with paranoia and anger; amazingly, you see actual character development (specifically, when John and T101 arrive at Dyson's house to prevent her from doing what she wants to) in her otherwise 2-dimensional character. And Furlong, as John, is not bad himself as the extroverted kid who's confused by the fact that everyone except his mom tell him his entire upbringing was based on a lie. The bit players all do their jobs well, particularly Earl Boen who plays the semi-sadistic mental hospital warden that stands between Sarah Connor and her son (until the T1000 makes a chilling entrance).
With these players set in motion, it's up to the script to deliver the real substance of the movie. (One often sees great performances in mediocre films... here the story transcends the performances -- an impressive feat.) The script delivers. The film is absolutely filled with great, classic moments (I counted TEN all-star ones during my last viewing), and they're evenly spaced through the movie. I mean, who doesn't cheer (at least inside) when Arnold steps out of the biker bar, fully clad in leather when "Bad to the Bone" music starts to blast? The guy absolutely bleeds coolness. And the T1000 absolutely bleeds evil. But, with so many great moments, you'd think the pacing would be a little uneven... not really! The film shifts from place to place with an ease that makes perfect sense, never giving you the time to start being a little nitpicking jerk, always driving forward, but always doing so thoughtfully and with attention to detail.
Of course, this wouldn't be an action movie without some action. There's plenty of it, and it's perfectly done. The CG effects for the shape-shifting T1000 were cutting-edge for the time, and still look great (whoever said differently below is simply incorrect) -- even if they're completely commonplace today. The stunts are completely insane in scale (at one point, a helicopter flies under a highway overpass; at another, a motorcycle jumps from the 2nd floor of a building into a flying chopper). (Probably, only the Matrix and the Lord of the Rings movies compare in terms of the level of stunt insanity.) And the gunplay is delivered in perfect Cameron-Schwarzenegger style (as opposed to the slo-mo John Woo-style) -- you'll see lots of heavy automatic and explosive weapons, and you'll see them used well. The film is violent, and somewhat bloody, but ALL of the mean-spirited violence is dealt by the evil characters, not the ones you root for (Quentin Tarantino fans: sorry). And then the truly amazing scenes that bypass acting are shocking and memorable -- just wait until the nuclear detonation sequence.
I'm not sure what else you would want in a movie. Probably moral content, and the movie has a very clear pro-human, anti-war message. The message is a bit stale, and the delivery IS, at times, a little heavy-handed (and some moments with the T101 seem just a bit unrealistic, towards the end), but the movie has heart, and that you cannot deny. Plus, it simply rocks. 10/10