Back in the early to mid 90s, I saw this video at Blockbuster all the time and thought it looked interesting; but it also looked "scary" and I knew my overprotective mom would never let me rent it.
It showed what looked like a robot or cyborg hand; the fingers were dark, metallic and pointy, rather like Freddy Krueger knives (but I know this wasn't one of the A Nightmare On Elm Street films). Most of the fingers were folded back, but the index finger was extended downward and just starting to poke into some water (oil?), which was rippling.
By the time I was old enough to rent it myself, it was gone (as Blockbuster itself is now, of course). Does this sound familiar at all to anyone? I'm sorry I don't remember anything else.