Terminator 2 is action but realistically its background and whatnot was Scifi with the HIGH quality special effects.
For action I might have to say it was the trend that for some reason in the late 90s action movies needed comedy. And not just one liners like bruce willis, like...breaks in action for jokes and sillyness. Everyone tried to do that and it just doesn't work usually..and it REALLY watered down action. While the series was a success, I gotta say RUSH HOUR 2 breaking RECORDs with that formula made no movie just a hardcore action film until like...JOHN RAMBO almost 10 years later.
BTW, big shouts to Stalone for resurrecting your hardcore ultra violent shoot em up with John Rambo, and Expendables. yes the expendables is a sloppy POS but so was Commando
its part of the genre at its best.