T2 is the best all around film, yes. But from a pure action standpoint, scene for scene, complete with an incredible repeat viewing ratio not seen since david beat goliath with a slingshot, Predator is the clear winner.
Also, like the running man and terminator, it's got a bit more going for it than just pure action with some interesting things to say about man, and war, and sport, etc. Plus the one-liners, the guns, the Shane Black script...I could talk about Predator all day. Easily my favorite action flick of all time..
Running man is slept on though