1. Gallium
    Of course Gallium has to win - it frickin' dissolves other metals. They don't have a chance against it. Oh and it literally melts in your hand - but hopefully not in your mouth.
  2. Bismuth
    Ooooohh the crystals, so fun to look at and more fun to make! Plus it's the most naturally diamagnetic substance around, almost to the point of levitation.
  3. Magnesium
    You know that brilliant bright white light in fireworks? That's Magnesium. Not only is it bright but it burns hot and slow - that glowing exploding dandelion shaped firework, after the initial burst, is basically a sphere made of burning magnesium, so bright you can see it as glowing white all the way from the ground. I hear it's good to eat some too - but probably only in very small pieces.