Islanders, Kings, Lightning, Maple Leafs, Penguins.
The Leafs ain't got much to work with that would fall into the knock your socks off category, I wish the Pens would bring back the mid 90s logo, and that would qualify, but Mario hates it, so doubt it. Lightning? Their current jerseys are easily the best they've ever had. What are they going to do, bring back the Microsoft WordArt logo? Unless they bring out the '96 alts, and well, that would certainly be an interesting decision. It would be noticed, for sure. Isles? Fisherman, clearly. Or maybe the "look at my dick" jersey is coming back? But seriously folks, theirs was leaked and it's pretty crappy, and not in an interesting way.
So that leaves us with the Kings. Purple or gold as a full time third would be awesome. A modernized purple set could certainly qualify as a dramatic move, and I could see them being quite popular.