Shaquille O'Neal 1998-99 SkyBox Molten Metal Fusion Titanium /250
While the design is not exactly original, the 1998-99 SkyBox Molten Metal Fusion is one of the nicest 90s inserts around.
The cards feature die cut technology where small holes are 'etched' into the card to form the portrait of the player featured. If I'm not mistaken, this was first used for the 95-96 Stadium Club Beam Team as seen in this mail month.