There's no way, of course, that "2" could hope to escape the shadow of the legendary original, but it's also overshadowed by "Vengeance" given that features such things as Bruce Willis and Sam Jackson's interplay and Jeremy Irons's terrific villain turn. It plays often like a rehash of the original (even making fun of it, like when Willis asks how it can happen to him twice). The villains are fine, but not anywhere near as memorable as Alan Rickman or Irons. And so on.
But I still really like it as a fun action flick and a worthy successor even if it doesn't quite compare to its predecessor and successor. The setting is great as an airport at Christmas is a fabulous setting for maximum carnage and chaos. Willis still has John McClane in this one as a beleaguered everyman thrown into a situation he didn't expect or want (guy just wants to pick up his wife and get back for Christmas with the in-laws) and we see him at arguably his most vulnerable at certain points. And it keeps the tradition of the first one by having even minor characters be memorable (like the cute Avis clerk who both aids and flirts with John or Holly's Taser-wielding seatmate). I frankly like watching both this and the original at Christmas as a pair for some good holiday-themed action.
I'd also add another aspect that stands out; this is the darkest and most brutal entry in the franchise. Not only does it have arguably the most graphic deaths of the series (see John stabbing the mook Baker through the eye with an icicle or Major Grant getting kicked into the plane turbine), but the villains are genuine terrorists in this one, not just using it for cover. Bill Sadler plays Lt. Col. Stuart as a cold-blooded sociopath with none of Hans or Simon's charisma or likable traits, which makes him arguably the scariest "Die Hard" villain (easily the most hatable; Sadler apparently considers it a compliment when people tell him how much they hate the character, because that's what he intended). And worst of all, THEY CRASH A PLANE. A plane with over 200 people on it, including children. And no one makes it out alive. You have to respect an action film with the guts to do that to show just how serious the threat is.