anything useful to me

liquid helium wink

the alchemist and boater answers: water
but the math and physics dropout in me would say: hydrogen
8)

I love the periodic table of elements. As a radiochemist I work with elements that many people have never heard of or often overlook.

Iridum is beautiful.
Technetium is neat because it does not occur naturally.
Seaborgium has a rich history behind it's name.
Roentgenium is fun because it is the most recently named.
But, liquid Helium is definitely the coolest.

Carbon :!:

You really mean cool? Not useful?

Krypton and Gallium are the coolest then.

europium all the way baby...\m/ -_-\m/

I think Liquid Nitrogen is the coolest.
It's very cold in the ;) sense, and it great fun in the 'Woah man, cool!' sense

I think feline's answer was part pun, as helium has the lowest melting and boiling points known; of course, liquid helium is a superfluid which helps.

personally, I have a soft spot in my heart for cesium which is rather beautiful both as a pure metal and in flames.

For me it's a toss up between osmium metal and bromine. Bromine is just so interesting in how reactive it is and the deep red-brown color of its liquid. Plus, it is the only non-metal that is a liquid at room temperature. It gives off a very thick colored vapor and does wonders on aluminum. hehe. Osmium is neat because it has that distinctive blue color and is so freaking dense. Plus, it's chemical behavior seems to change depending on its physical state. Five grams of powdered/sponge osmium will rapidly oxidize on exposure to air and give off the nasty smelling, and very toxic, compound osmium tetroxide. Yet if you have five grams of osmium melted down into a solid button, it's completely stable. That just seems so interesting to me.