Die Hard:
It's a classic, no disputing that, I really wish more action films were set at christmas. I like that McTiernan wasn't in a hurry to get to the next set piece, the action scenes feel organic, you can see McClane clearly struggling to take these guys down. "Shit lady, you think I'm orderin' a pizza?"
Die Hard 2:
I have a soft spot for this, maybe it's for nostalgic reasons, it's a blatant rehash of the first film, Renny Harlin has nowhere else to go but to up the adrenaline factor. I like that McClane get's the holy hell kicked out of him in this film, again, he really struggles to defeat the villains, I really like it that he's out of his depth and just prevails through sheer will and inventiveness.
Die Hard with a Vengeance:
I like that they took a different approach, McClane is the cop we'd heard about taken to it's limits, his marriage is over and he's on suspension. It's a cliche but we buy it because he's John fuckin McClane. The film is pretty much a buddy comedy. Jackson and Willis's chemistry singlehandedly elevate this film and McTiernan's direction is just so assured.
Live Free or Die Hard:
As an action film it's not bad but as a fourth installment of the series it just doesn't work, the villain is weak and just really not a threat to McClane at all, say what you want about Sadler and Amos in DH2, at least they felt threatening and looked like they were having fun with their characters. There was a vague realism to the other films but that was sadly missing here, Maggie Q surviving a head on collision from an SUV? Sorry, I don't buy that for a secong.